aaz-jx turbo oil leak
Printed From: The Brick-yard
Category: T3 Section
Forum Name: T3 Engine Upgrades
Forum Description: Forum for tuned or alternative engines.
URL: http://www.brick-yard.co.uk/forum/forum_posts.asp?TID=60405
Printed Date: 20 Apr 24 at 03:02
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: aaz-jx turbo oil leak
Posted By: dancooper
Subject: aaz-jx turbo oil leak
Date Posted: 09 Dec 10 at 12:43
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Hi all, I was hoping someone maybe able to help with an ongoing problem with a leaky turbo. I have put an AAZ motor out of a 93 Golf in my friends 89 syncro in place of the original JX motor using the JX sump, oil pick up pipe, exhaust manifold and turbo. The oil return pipe is the brick-werks item. The engine was filled with 4.5 lites of oil and the JX dipstick re-marked. The original turbo had a small amount of play in the bearings but nothing too serious so I thought I'd re-use it and see how it went. When I first started the motor oil leaked out of the turbine outlet and the join between the turbine housing and compressor. So the turbo oil seals appeared to be knackered, I wasn't surprised as the vehicle had stood still for 4 years. Ive just received a recon turbo and fitted it. As per normal before fitting it I put fresh oil into the oil inlet and once fitted I cranked the engine with the fuel solenoid disconnected until oil ran out of the oil return fitting on the turbo. I then connected the oil return line and fired it up without the exhaust on, after a minute i could see oil running from the turbine outlet just like before although it doesn't leak from the compressor side. Could it be a dodgy recon turbo or have I done something wrong? I have removed the oil return pipe and checked for blockages, none found. I have noticed the brick-werks oil return pipe being longer than the original one (i know its meant to be) meaning that it has a bit of a u bend to it before it re-joins the sump, could this act as a blockage? I doubt it as the oil is being pumped down hill but I'm clutching at straws. I have re-checked the turbo for shaft play, none found. I was thinking of removing the turbo and checking the inside of the exhaust manifold for oil in-case there is something catastrophically wrong with the engine causing it to pump oil into the exhaust but at the moment I cant bear to even look at the wretched thing!!! I'm going to contact the turbo suppliers who will probably tell me to send the turbo back to them, shame, I live in France and pretended I live in the uk to get around postage problems ha ha Any help would be greatly appreciated. Thanks Dan
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Replies:
Posted By: Inspector
Date Posted: 09 Dec 10 at 16:03
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What is the overall condition of the engine? I was just thinking that if the pistons/rings are too worn, there might be too much pressure inside the crankcase. My friend had a problem with AAZ: new turbo, reconditioned cylinder head, and engine was consuming oil enormously. The oil didn't trip out, but was burned. New oversize pistons did the job. Your problem is different, but would it be possible for the assumed extra pressure in crankcase to push oil back via the return line to turbo seals? When I bought my AAZ and disassembled it, I found it to be in really bad condition although the engine was sold as a fully working one. So the two AAZ engines that I have seen, were both the same.. |
Posted By: dancooper
Date Posted: 09 Dec 10 at 20:24
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I'm not sure of the overall condition of the new motor,bought on ebay, for £275 already removed from the car with apparently 98,000 miles on it. Crankcase pressure seems normal to the hand but I know thats not an accurate test. I don't have a compression tester and I'm not about to pull it apart to check, I don't have time, I was supposed to move back to the UK last week but I'm still here in France messing around with this crap! Anyway, Ive sorted it. I remember noticing the modified Brick-werks oil return pipe has a much smaller internal diameter and also it just seemed too long leaving a u bend in it. I spoke to the technical support from the suppliers, turbo solutions and they seemed to think that a restricted oil return pipe would be enough to cause this problem. So I got the original, larger oil return pipe, put it in a vice and gently straightened it out as much as I dare till it was long enough to reach the turbo, fired it up, problem solved. I guess there must be more crankcase compression than I thought, stopping the oil flowing down the smaller oil return pipe???? I dunno! Now that its not pumping oil out the exhaust there isn't any blue smoke so the rings cant be letting much oil past them, I wander how much cylinder pressure is getting past. Anyone else had a problem like this? I posted without checking to see if anyone else had experienced this. Brick-werks must sell quite a few of them so if they were causing a problem we'd know.
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Posted By: max and caddy
Date Posted: 09 Dec 10 at 23:39
| intresting stuff. mine sups oil but no smoke and has a brickwerks stlye return pipey on it. |
Posted By: dancooper
Date Posted: 11 Dec 10 at 00:14
| back in the late 90's i worked in a vw dealership, when cars with the td engines came in for a service they would regularly have no oil registering on the dipstick. They really do seem to use a lot of oil but never burnt it on road test. During the service, other than the occasional standard rocker cover gasket modification, oil leaks that would explain such a loss of oil were never found either, odd. |
Posted By: jebiga41
Date Posted: 11 Dec 10 at 01:25
same here also with a new turbo
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max and caddy wrote:Posted By: dancooper
Date Posted: 11 Dec 10 at 22:12
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jebiga41, have you got oil leaking from the joint between the exhaust and turbo, thats what I first saw, if so could be oil not being able to get back to the sump from the turbo and pushing it out the turbo seals into the exhaust. Just a thought.
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Posted By: Baxter
Date Posted: 12 Dec 10 at 00:22
| Disconnect the engine breather and try it again. |
Posted By: corvusstation
Date Posted: 12 Dec 10 at 19:34
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I'll share my experience with you! My mechanic fitted a fully rebuilt aaz (so new to all intents and purposes) and got the jx turbo rebuilt at the same time. Used the Brickwerks oil return line etc. We had oil from the exhaust: occasional blue smoke and evidence of oil in the exhaust. My mechanic was so concerned that he removed the turbo and sent it back to the rebuilders together with a bollocking. They stripped it and found nothing wrong so sent it back. They suggested it would 'bed down' with use so it was refitted and I used the van to go on holiday but kept a watch on what was going on. A couple of thousand miles later the blue smoke and oil from the exhaust had vanished so they were right - it did indeed 'bed down'. Hope this is of some use! Cheers |
Posted By: dancooper
Date Posted: 12 Dec 10 at 19:56
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I asked the technical support guy at turbo solutions if a turbo needed time to bed down and he reckoned it didn't, it would never be better than it could be when it was taken out of the box, also they're bench tested within the operating parameters to see if thy're going to leak. I restrained from giving the guy a bollocking before I knew whether it was the turbo or something else at fault, payed off, he was real helpful.
Baxter, if I refit your oil return pipe, disconnect the breather and the oil leak doesn't reappear this would prove crankcase pressure is too high right? Is this why some people have the breather running up the side of the van or out of the back with a filter on the end of it? To get rid of excess crankcase pressure? Can the breather connector on top of the rocker cover be serviced/cleaned? If this was blocked would it stop crankcase pressure escaping into the inlet system? Thanks |
Posted By: Baxter
Date Posted: 12 Dec 10 at 21:39
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Lots of people write turbos off as kanckered because they have some oil in them or "the seals have gone" I don't think I have ever changed a turbo because "the seals have gone", it's too easy to blame the turbo, usual thing, people don't fully understand them so when they get a problem the most likely cause is the thing they know least about. Same stands for ECU, injection pumps etc etc.
Please remember that the engine breather exits pre turbo, so if the engine is breathing heavily and the breathing system is left unmodified then oil WILL make it's way down the breather pipe into the inlet tract to cause smoking.
Remove the pipe before the turbo and check for oil there.
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Posted By: VWsirhc
Date Posted: 18 Jan 21 at 19:32
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Hello all, I just have the same problem. I put an AAZ engine from a 97 Vento with
148.000km in my 87 T3 in place of the original JX engine using the JX sump, oil
pipe, intake connection, exhaust manifold and turbo with the Brick-werks turbo
spacer. The oil pump itself is from the AAZ. The engine was filled with 4.5
liters of oil. When I first started the engine, after a
dozen or so seconds, oil was leaking from the turbine exhaust and
compressor exhaust. That's why I renewed the turbo core, but the problem
remained. The problem was not solved with a second and a third used turbo. In
the meantime I have also tried three different return lines with 7mm inner
diameter in vain and another used oil sump. I measured the pump pressure at the
output of the pump at the oil filter housing. When the engine is cold, this is
5 bar at idle speed and the pressure drops when the engine is warmed up. If the turbo oil return is disconnected
from the plugged sump for a few seconds while the engine is running, the oil
will drain well from the line. To be sure of a good crankcase
ventilation, I always removed the oil filler cap from the valve cover. Oil is still leaking from the turbo. Do you know what to do? |