Damn thing still smokes after engine overhaul

New poster! (less than 10 posts)

Hey everyone,

I've posted an issue here a few months ago regarding my smoking car...
It appeared that one of the bottom piston rings was missing (!!!) and that the liners were as smooth as a baby's bottom. Not good. So I replaced all the liners, pistons and rings with brand new ones, so basically I now have an engine that's as good as new. I also got a brand new big turbo, so when I started her up this morning for the first time, I assumed it wouldn't smoke anymore. Well... it still does. I've driven it for about 50 miles now, so all of the excess oil should be burnt by now. But it still smokes (blue) like crazy... only a little less than with the old pistons and liners. I've checked the turbo oil return hose and breather system and everything is fine. What the hell could still be wrong here? I'm at a loss... :cry:

New poster! (less than 10 posts)

Bit of a strange problem seeing you have changed p&l's & turbo !

Maybe the oil you are using is too thin ?

or your breather system has problems......

also check that your carb is set up correctly, I have had problems where my carb was F***ed and was over fueling causing it to smoke.

Can't think what else it could be :confused:

New poster! (less than 10 posts)

ah remebered one more thing....


Check to see if the exhaust has oil in it from where the engine was passing oil before the overhaul, sometimes it can take long the burn the excess oil away.

New poster! (less than 10 posts)

Check the turbo oil return isn't kinked/blocked, also make sure all breather hoses are ok. Might be worth doing a comp test aswell.

New poster! (less than 10 posts)

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Originally Posted by Roach

New poster! (less than 10 posts)

Bit of a strange problem seeing you have changed p&l's & turbo !

Maybe the oil you are using is too thin ?

or your breather system has problems......

also check that your carb is set up correctly, I have had problems where my carb was F***ed and was over fueling causing it to smoke.

Can't think what else it could be :confused:

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My carb is fine... and overfueling should produce black smoke, not blue smoke, right?
I'm using standard mineral 15W40 oil which I'll swap for semi-synthetic after it's run in properly. And I checked the breather system 2 times... it's all fine. Maybe they sold me a dodgy turbo and it's leaking oil... could be...

wip the turbo elbow off, if you've got oil you have probs! turbo oil seals?

New poster! (less than 10 posts)

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Originally Posted by jantheeven

New poster! (less than 10 posts)



My carb is fine... and overfueling should produce black smoke, not blue smoke, right?
I'm using standard mineral 15W40 oil which I'll swap for semi-synthetic after it's run in properly. And I checked the breather system 2 times... it's all fine. Maybe they sold me a dodgy turbo and it's leaking oil... could be...

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Black smoke correct !!

15w40 is good should'nt pass the turbo seals

Maybe the turbo is dodgy its the only thing that will really smoke seeing as the p&l 's are new.

Maybe make a blanking plate for where the turbo meets the manifold and run it with out the turbo connected and see if it still smokes........:smokin:

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Originally Posted by Roach

New poster! (less than 10 posts)




Maybe make a blanking plate for where the turbo meets the manifold and run it with out the turbo connected and see if it still smokes........:smokin:

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wheres the exhaust gases suppose to exit:confused:

Valve guides worn or stem seals gone ??

Only other thing i can think of Jan...

New poster! (less than 10 posts)

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Originally Posted by 5teve L

Valve guides worn or stem seals gone ??

Only other thing i can think of Jan...

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I've had the head checked when it was off... valve guides were fine and stem seals replaced...

New poster! (less than 10 posts)

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Originally Posted by raj

wheres the exhaust gases suppose to exit:confused:

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good point......

New poster! (less than 10 posts)

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Originally Posted by Brigsy

New poster! (less than 10 posts)

Check the turbo oil return isn't kinked/blocked, also make sure all breather hoses are ok. Might be worth doing a comp test aswell.

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Which oil return hose are you using, ph1 or ph2? ph1 is pretty restrictive imo..

New poster! (less than 10 posts)

I had to make a custom oil return, since my original ph2 hose didn't fit the new turbo... made it out of an old water hose and it's not kinked or anything... breather hoses are also fine... no blockages or anything

Try taking the exhaust off, straight off the turbo elbow, it will be loud but you can see if it still smokes, as it has been suggested, it could be oil in the exhaust burning off as said above, if you have changed things as per OP then it baffles me to why it still smokes.
Normally it's down to Turbo, rings, stem seals, blocked breather pipes.....
What compression reading do you have now ??

New poster! (less than 10 posts)

Take turbo off & run it without, see if it still smokes.

New poster! (less than 10 posts)

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Originally Posted by Brigsy

New poster! (less than 10 posts)

Take turbo off & run it without, see if it still smokes.

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How do I do that?? What do I do with the water and oil hoses... not to mention the exhaust gases?

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Originally Posted by jantheeven

New poster! (less than 10 posts)



How do I do that?? What do I do with the water and oil hoses... not to mention the exhaust gases?

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You can run the oil feed to the oil return & the water ones just join together, exhaust gasses, well they would just have to come out under bonnet, try it with just th turbo 1st, take the exhaust off from the elbow, at least thats simple & will eliminate if the exhaust is full of oil....

I know the breather system has been mentioned but I had a similar problem and it turned out to be the rocker cover breather being blocked.

New poster! (less than 10 posts)

Nope... breather system is fine... I'm guessing it's the turbo (again). Probably the oil seal :(. Is that an expensive part?

Everybody seems to be assuming that because the pistons and liners are new it cant be them. Why not? maybe a one or more of the rings is fitted wrong, or the engine was not run in properly (im not suggesting you've done these things Jan, just pointing out that because its new it doesn't mean you can assume it is correct)

But as has been said above though eliminate the obvious first, oil in exhaust, turbo, valve guides.

btw- turbo oil seals are not an expensive part, 15-30euros should get a set, getting someone to strip the turbo and fit the new seals however will be expensive.

Just make sure its not running so rich that its bore washing the liners!

It doesnt sound MEGA rich, but if it was it could take only a few miles to kill a new set of rings and liners.

Hope get it sorted.

New poster! (less than 10 posts)

Thanks for all the suggestions so far guys... I phoned the turbo supplier today and explained the problem. Of course, he said that he couldn't imagine that the turbo is maybe dodgy, especially after a full overhaul. He asked what kind of exhaust I have... and I have the k-tec side exhaust system. He said that the exhaust possibly doesn't create enough back pressure, causing the turbo to leak oil??? Anybody had experience with that?

Jan, have you tried removing the turbo from the manifold, starting the engine, then seeing if the blue smoke comes from the manifold? If it does, you know it's engine related (assuming there aren't any traces of oil that's in the intercooler/boost circuit, and thus, the oil vapour is making its way into the engine thus so). If it doesn't, it's turbo related.

A wee bit of back-pressure may be needed to keep the seal in place, but I thought once they had bedded in as such, it wasn't as important.

Unfortunately, turbo suppliers/manufacturers will never ever admit their units are at fault. I had many a discussion with Turbo Dynamics back in the day (had a series of problems with their MD28 & MD84 blowers), but they never backed down & held their hands up. Only way you're gonna know for sure, apart from trying the above, is to put a known, solid, good turbo on your car, and see if the smoke is still present.

Of course, all of this is also assuming that there isn't any oil sitting in your exhaust system/silencer box?

Btw, if there is oil present in the exhaust, it'll defo take more than 50 miles to fully burn off. I know this from past experiences...

New poster! (less than 10 posts)

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Originally Posted by Mart

Btw, if there is oil present in the exhaust, it'll defo take more than 50 miles to fully burn off. I know this from past experiences...

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Yeah there is definately oil in the exhaust... I saw an oily wet spot at the connection between the front piece of pipe (that connects to the turbo down pipe) and center part. But I could also see an oil spot underneath the turbo on the gearbox.......

New poster! (less than 10 posts)

...and isn't it possible perhaps that the turbo needs to run in too? I mean... its internals are completely new. Could it be that everything has to bed in before sealing properly, just like the piston rings? The turbo dude said that used turbos have some carbon deposits on the shaft, making it seal better...........

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Originally Posted by raj

wheres the exhaust gases suppose to exit:confused:

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I've done this before many years ago you use a an old T2 or knackered turbo that rear exhaust housing that will fit the GTT manifold and cut a piece of metal that will fit on the 4 x turbo core mounting bolts tighten them up to keep the metal sheet in place and the gasses will escape the normal way, the car ran good just very very slow :laugh: Oh yeah you will need to join the oil feeds and water feeds aswell.

Yeah there is definately oil in the exhaust... I saw an oily wet spot at the connection between the front piece of pipe (that connects to the turbo down pipe) and center part. But I could also see an oil spot underneath the turbo on the gearbox..........and isn't it possible perhaps that the turbo needs to run in too? I mean... its internals are completely new. Could it be that everything has to bed in before sealing properly, just like the piston rings? The turbo dude said that used turbos have some carbon deposits on the shaft, making it seal better...........

No, i don't think turbo's have to run in Jan, all the turbo's i've fitted i've just done an oil & filter change & away we go, maybe running on low boost for a little while & then going max... What oil are you using out of interest?
Steve

PS Have you not got another turbo you could try ?
Also if it's a new engine build it is possible for swarf & fillings from the bearings to travel round in the oil & knackering the turbo :(

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Originally Posted by 5teve L

No, i don't think turbo's have to run in Jan, all the turbo's i've fitted i've just done an oil & filter change & away we go, maybe running on low boost for a little while & then going max... What oil are you using out of interest?
Steve

PS Have you not got another turbo you could try ?
Also if it's a new engine build it is possible for swarf & fillings from the bearings to travel round in the oil & knackering the turbo :(

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Hey Steve, I'm using cheap mineral 15W40 oil for the running in... and it's not a new engine, I just replaced the liners, pistons, rings and conrods bearing shells. I think I still have my old turbo hidden somewhere ;) Should work fine...

Before I try a different turbo (which turns out I don't have anymore)... I'll try cruising for a 1000 miles or so first. Several people on the Dutch forum said that it is very possible that the new turbo does need running in and that it isn't uncommon for new turbos to cause lots of smoke... we'll see... keep you posted ;)

Never heard of bedding a turbo in. It'll defo help matters if you burn off all that oil residue sitting in your exhaust system though.

How many miles should that usually last then?

http://www1.istockphoto.com/file_thu..._of_string.jpg

?

Hahaha... I'm sorry... forgive my poor English ;)

I meant: how many miles does it TAKE before the oil in the exhaust system is burned off? (assuming there's lots of it in there)

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Originally Posted by jantheeven

Hahaha... I'm sorry... forgive my poor English ;)

I meant: how many miles does it TAKE before the oil in the exhaust system is burned off? (assuming there's lots of it in there)

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http://www.usingenglish.com/referenc...of+string.html

Cheers Andy! ;) I wasn't being ignorant; it's just a question that can't be replied back with an exact answer.

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Originally Posted by Mart

Cheers Andy! ;) I wasn't being ignorant; it's just a question that can't be replied back with an exact answer.

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which means you don't know, which means your ignorant - the dictionary never lies :laugh:

sorry... just hoped I could get some sort of indication... but I get the point...

:laugh: Ok, 132 miles with plenty of full boost action. How's that? ;) :D

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Originally Posted by jantheeven

sorry... just hoped I could get some sort of indication... but I get the point...

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Join us at Nurburgring in October. By the time you've driven there, and driven a few laps, the exhaust should be clean of oil...unless your blower is bleeding it out.

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Originally Posted by jantheeven

sorry... just hoped I could get some sort of indication... but I get the point...

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imagine you put some oil inside the back of your exhaust, how long do you think it would take to get it hot enough to burn the oil off?

There is a good chance that you never will.

What you should see is less oil burning as time goes on.

132 miles huh? Sure it's not 133? :laugh:
But again... I get the point... thanks anyway guys ;)
Just keep making fun of the Dutch! :D

In fact I am going to the Ferrari Racing days at the Nürburgring on the 4th and 5th of october... when is the RTOC track day there?? It's just 100 miles from where I live...

Jan, defo not making fun of you mate. It's just a question that can't be answered.

RTOC Nurburgring visit is 18th-21st October :)

Great... I still have leave from work then! Maybe I'll join you guys then for a day ;)

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Originally Posted by Mart

http://www1.istockphoto.com/file_thu..._of_string.jpg

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I'd say about 9cm from that pic

:laugh:

I just removed the turbo from the car... no oil present in the elbow... so that's a good sign, right? I did notice a small oil leak between the turbine and compressor sections, on the outside that is...

Please guys... any wise comments on this? ;)


By the way... Maurice from MB Car Performance in Holland (he said he knows some of you guys, like Steve) will maybe also come to the ring in october with me... should be fun ;)

New poster! (less than 10 posts)

ok....

start the car.
pull the black oil seperator pot off the 'return to sump' pipe. rev the car for 30seconds. does the car stop smoking?

does the smoke actually smell oily or fuelly? get a helpful assistant to stand by the exhaust and give their verdict....

when you rebuilt the pistons, did you make sure that you put the rings on the correct way round? if you didnt, then this will be your problem.....

did you take the valves out and test for valve guide wear? and regrind the valves in?

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Originally Posted by The Wizard

New poster! (less than 10 posts)

ok....

start the car.
pull the black oil seperator pot off the 'return to sump' pipe. rev the car for 30seconds. does the car stop smoking?

does the smoke actually smell oily or fuelly? get a helpful assistant to stand by the exhaust and give their verdict....

when you rebuilt the pistons, did you make sure that you put the rings on the correct way round? if you didnt, then this will be your problem.....

did you take the valves out and test for valve guide wear? and regrind the valves in?

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Thanks Wiz...
I already tried it without the oil separator pot and it still smoked. Breather system is triple-checked and fine. Smoke is blue and smells very oily. I'm positive I put the rings on correctly, as an expert showed me how to do it on one piston so I could do the other three myself. I took the head to a shop to have the stem seals replaced and to have it checked in general and they found no problems...
So you think it's not turbo-related then?

New poster! (less than 10 posts)

did you make sure the letter/numbers written into each ring were facing upwards?

did you change anything else, like crank bearings?

did you change the liners and pistons outside or in a dusty workshop?

how many days was the engine 'open to the elements'? or was it completed in 1 day?


im covering all bases.

New poster! (less than 10 posts)

what oil pressure are you running?

does your turbo oil feed have a restrictor in it?

could be just oil still in the zorst.

once you have done all of the above to see if its engine or turbo.

here is how you get the oil out of the zorst

there are two ways
1: remove the exhaust and stand it up on end so all the oil drains out ( this dont get all the oil out but does help)
2: this is the method i prefure : hold the revs up at around 2,000 to 3,000 not driving and keeping a real close eye on the engine temp
driving cools the zorst
get the zorst as hot as you can and burn the oil out
http://i25.photobucket.com/albums/c5...ginewarmup.jpg:laugh::laugh::laugh:

Yes I'm positive the numbers on the rings faced upwards, I took special care in that. I also changed the conrod bearing shells, not the crank bearings. I changed everything in my own garage... took a couple of days, but I cleaned everything thoroughly before fitting the new stuff. Oil pressure whilst driving is around 4 bar, when idling & warm engine down to between 1 and 2 bar. I'm not sure what you mean by an oil restrictor. This is the oil feed that I use:
http://www.k-tecracing.com/show_product.asp?id=40

Here's a pic of the turbo oil leak... I'm not sure what this means. But you can easily see the leak at the bottom of the turbo... it's burned black due to the extreme temperatures...

http://i54.photobucket.com/albums/g8...5092008001.jpg

Please guys... any comments on this picture? :cry:

Turbo oil seal kaputt by looks of it if oil is leaking out of there, or oil return to sump blocked/kinked badly backfilling the turbo.

The tomcat turbo's always leak out of the bottom of the exhaust housing when they fail like in your pic.

Hmmm... well the oil return is fine really... I've checked and double checked that... but the turbo is brand new... how can it have bad oil seals then??

Might just be a crap built turbo.

probably... god damn turbo supplier always tries to put the blame on my car... this is wrong, that is wrong... damn you NOTHING IS WRONG WITH MY CAR!! :mad:

shall i tell you a little story?

once upon a time a cheeky young chap, jantheeven was his name, decided to do an engine rebuild on his renault 5 gt turbo. he changed the big end bearings and fitted a new turbo. the engine as it started to wear in produced a bit of swarf, which dutifully went round the turbo, causing it to smoke. then end.

ERR, question....


what happens if I did not notice the way i put the rings in only in one bore ?

will it be a biggie ??

dont know if i can be bothered to strip the head and sump off to check.

Will a comp test tell the tail ?

:o

Well apparently the way you put in the rings matters a lot... don't know if a comp test will reveal a problem there... I'm no expert on that subject.

Anyway... I took my turbo to 2 different turbo suppliers today and had it checked. It appears that the oil leak is easily fixable. My custom turbo has a removable oil return pipe, which is welded to a flange and has to be bolted on to the turbo with 2 bolts. And it's sealed with a gasket... which my turbo didn't have!! They gave me a gasket and sent me on my way, assuring me that the turbo itself was fine and that it didn't have a dodgy oil seal... otherwise there should be a presence of oil in the exhaust part... and that's clean. Happy times! ;)
So now I just have to burn off all that oil in the exhaust...
Finally... light at the end of the tunnel :laugh:

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Originally Posted by Sparkie

shall i tell you a little story?

once upon a time a cheeky young chap, jantheeven was his name, decided to do an engine rebuild on his renault 5 gt turbo. he changed the big end bearings and fitted a new turbo. the engine as it started to wear in produced a bit of swarf, which dutifully went round the turbo, causing it to smoke. then end.

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I'm cheeky? Hmmm... :rolleyes:

By the way... thanks for considering me at an age of 31 to be a young chap :laugh:

when i was 2, you were being kept warm by your dads Y fronts. you are a young chap to me...just! :laugh:

any news on wever youve solved ya problems yet then m8?

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Originally Posted by tom t

any news on wever youve solved ya problems yet then m8?

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Well... actually I had 3 problems: the blue smoke, the oil leak at the turbo and the high water temperature whilst slow driving and stand still. The oil leak is fixed and the turbo itself is fine fortunately. The high watertemp was caused by the fan switch connector which was on the wrong way around and the blue smoke is probably just old oil in the exhaust from before the rebuild... so that just needs to burn off :)

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Originally Posted by Sparkie

when i was 2, you were being kept warm by your dads Y fronts. you are a young chap to me...just! :laugh:

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LOL okay pops :laugh:

Anyway... is it a good idea to drop the oil again now? I've driven about 50 miles... no freeway... not revving more than 3000rpm

yes change the oil.
i dont think you can actually change the oil too much when you are running it in. :laugh:

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Originally Posted by Sparkie

yes change the oil.
i dont think you can actually change the oil too much when you are running it in. :laugh:

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oil filter too I presume?

best to play it safe.

Thanks for all the help guys... I've modified the breather system and installed the original ph1 turbo oil return hose and it doesn't smoke any more!

So I'll be joining you next Sunday at the Nordschleife!! :smokin:

New poster! (less than 10 posts)

Just curious, What did you mod on the breather system?

and what did the original PH1 oil return help with? I thought the phase 1 return was narrower that the PH2? assuming you mean you switched from ph2 return to ph1?

:confused: :)

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Originally Posted by SPENCER

New poster! (less than 10 posts)

Just curious, What did you mod on the breather system?

and what did the original PH1 oil return help with? I thought the phase 1 return was narrower that the PH2? assuming you mean you switched from ph2 return to ph1?

:confused: :)

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I added an oil catch tank just to be safe, due to my high boost pressure (22 psi).
I had a ph2 car & engine, but I swapped the engine for an overhauled ph1 engine, so my ph2 oil return didn't fit anymore. So I had to make an oil return myself out of old water hoses. And because the diameter of the turbo's oil return pipe was bigger than the pipe going to the sump, I had to fit a small diameter hose into a bigger hose :rolleyes: It appeared that the inner diameter of the small hose was just too small, compared to the original ph1 oil return hose. ;)

you want to watch those water hoses with oil, the oil will kill them.

Binned them ;)
Now have the original Renault oil return hose :agree: