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mt · Posted: Wed May 25, 2005 9:46 pm Post subject: Oil leak

I have an oil leak, it's only dripping but it drips straight onto the exhaust and starts smoking so i need to sort it sooner rather than later. Only problem is i don't know where it's leaking from, mechanic was under the car yesterday and couldn't work it out either.
The pic is of the left hand side of the engine taken from underneath (block in the top of the pic, head in the botoom). In the pic it seems to be coming from bolt 1 with the red cross, and the bolt next to it with the yellow cross. The two bolts marked with yellow crosses weren't in there yesterday, they were just threads which i think is as standard, but my mechanic doesn't think there should be any oil there as it's the block and put bolts in to see if it would stop the flow. He also thinks the bolt with the red cross is a water release so doesn't know why there's oil there either.
Does anyone have any idea where the oil could be coming from?

tvatavuk · Posted: Thu May 26, 2005 1:33 pm Post subject:

Hi MT, I'll send you diy 4x4 on friday.
Yes red cross nut is for coolant relese, obviously since other two were allready open and you didn't lose any coolant.

0. Are you sure that it is engine oil? (and not brake fluid from clutch slave cyl, or servo wheel transmision fluid)

Engine oil could be leaking down from oil filler tube, sensor or leaking from gasket between head and block.
In case breather tube from oilfiller neck is not connected to air intake plenum as it should but it is running oil fumes into air, you have also one suspect more.
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Tino Vatavuk
Little black dress which replaced Alfa Romeo 33 S 16v Permanent 4 GMo

Chris Notsis · Posted: Thu May 26, 2005 2:57 pm Post subject: Oil leak

If you look at the join between the head and block, near the exhaust manifold, you will see what appears to be the start of the leak. It is possible the leak is from the head gasket along the line between the two exhaust manifolds. The oil is heavily carbonised, suggesting it is coming out of this gap under heated pressure. At some point the head was off, re-fitted and possibly not correctly tensioned. One way to confirm is to completely clean the area and then see the actual origin.
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Chris Notsis

paddy granger · Alfa Sprint Joined: 12 Aug 2003 Posts: 248

gritsop · Posted: Thu May 26, 2005 11:43 pm Post subject:

Hi,

MT, does your mechanic has experience from Alfas and especially boxers?

I 've read in your post that the mechanic "thinks" that red bolt is for coolant, and has installed two bolts to "see" if possible oil leak originates from the thread! These threads are for keeping the engine block at desired positions when engine is on the special bed for overhaul!

Please accept my tone but my opinion is that these are just experiments rather than actual way to trace the leak. Embarassed

I would agree with C.Notsis that the best to do is clean the area and keep an eye on it to see where it comes.

Regards
_________________
Thanassis Gritsopoulos
1991 Alfa 33 1.4 IE
2001 Alfa 147 1.6 Distinctive

http://www.alfa-restoration.co.uk
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mt · Posted: Fri May 27, 2005 11:00 am Post subject:

Thanks for your responses.

I barged my way round to my friend's parent's house last night, jacked the car up and cleaned the area as best i could. Let it run for 15 minutes, no leak. Took it for a 10 minute drive, got back and checked it but still no no leak. Drove home, checked it, no leak.
Drove to work this morning, checked it, oil dripping onto the exhaust but i can't get under the car find out from where from. Typical! Took a couple of 'blind' pics though so i'll see if i can spot it on them later.
Chris, can see what you mean about where the oil seems to be originating from, will definately be watching for that later.

Oil level has dropped slightly, in 400 miles it's gone from the middle of the marks to near the lower mark. I'm 80% sure it's oil but it does seem a bit thin, smells like burning oil though. Will check the clutch cylinder to be sure but i don't think it's that, never rule out the impossible with Alfas though!

Cheers Tino, look forward to doing that at the weekend. Will check out the oil filler tube, i'm praying it's something as simple as that.

Gritstop, can see why you're dubious about the mechanic. I've known him years, he's an independant Alfa specialist and does have vast experience of boxers. Unfortunately his ramp only lifts 3 foot off the ground so it's still tricky under there, but it did look like oil was dripping out of the thread of that yellow bolt rather than flowing into it and dripping out, which confused him as he was sure that there should be no oil there. SO he put a bolt in there as it couldn't do any harm and would rule that out. And when i said 'thinks' i probably mislead you, he knew the red bolt was for coolant.
We'd just changed the cambelts before checking the oil leak and the car was at running temp which meant the exhaust was too hot to touch, which made it hard to investigate the leak properly. He thinks the head gasket is fine, i suggested changing it at the same time we did the belts but he was sure it didn't need changing.
Hopefully he's right Confused

I think i need to get it on a proper ramp, clean it and get it leaking again while it's on the ramp. Failing that i can only assume it will be an engine out job Shocked

Better try and save some money for some new cams and pistons then!

Chris Notsis · Posted: Fri May 27, 2005 2:21 pm Post subject: Oil leak - The Saga!

The oil residue is consistent with the colour of engine oil that has been exposed to high temperature BEFORE it got to where it is, then has been hardened by the surrounding air temp from the exhaust mainfold. What you now have is the sticky residue called 'aromatic hyrdocarbons' (found also when petrol residue (pink) sticks to external surfaces).

Oil leaks at that part of the head gasket are considered 'external' so any internal testing of the cylinders for leakage would find nothing wrong. It is not a combustion chamber issue (yet). The leak is more associated with the head bolts that are closer to the outer edges of the head than the inner. If these bolts, say only one, are undertorqued, then a leak at this point is very likely. It is possible to slow the leak using a good quality 'oil stop leak' additive, but it seems that it may not work in your case. One thing to try is to re-set the head bolts - cold, back off the bolts then re-set them, as well as using the additive. It is still a temporary measure and a head removal may still be necessary to replace the gasket. At the moment, slowing the leak is the aim until you are ready to go the next stage; compression is not affected.

Chris.
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Chris Notsis

mt · Posted: Fri May 27, 2005 3:34 pm Post subject:

Thanks for that info, it's so far above my level of knowledge that i can only assume you are right.
What are the implications of me driving the car as it is until i can get it sorted? Might only be a couple of weeks but i need to do distance in that time. And i fully understand i am the only person responsible for any decisions i make based on the info i receive here Wink

Chris Notsis · Posted: Sat May 28, 2005 2:31 pm Post subject: The Oil Saga

Sorry - I don't mean to make you dizzy with technical mumbo-jumbo! It's often a habit I find hard to shake.

You should have no problems driving anywhere and at any speed. Just keep an eye on the oil level from time to time. Where the leak is, there is little risk of coolant leak. The oil leak itself would not be considered 'major' or even 'of concern' at this point.

Cheers.
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Chris Notsis

mt · Posted: Mon Jun 06, 2005 11:08 am Post subject: Re: The Oil Saga

Thanks for your response Chris, gave me confidence that i wasn't gonna damage it last week. Car is at the garage today, asked them to diagnose the oil leak and they say they can clearly see it leaking out of the feeder pipe that goes from the sump to the head on that side so are gonna replace it. Is that the aluminium one in the shot above?
Because i'd mentioned the head gasket to them they checked that and said it's definately not coming out of there. They're also doing the water pump (re: water leak thread) so it should all be sorted in the next coupla days, can't wait!

tvatavuk · Posted: Mon Jun 06, 2005 5:42 pm Post subject:

Yes that is the one on picture.
They rearly start to leak, but if you remove them and put back, then they start to leak on their gaskets. Every time you unscrew them you should put in new gasket, and they are thought to find. My also leak, there was already silicone put there by mechanic but didn't help, I'll try to find out some better silicone/gasket in tube because new one can be bought here in Croatia.
_________________
Tino Vatavuk
Little black dress which replaced Alfa Romeo 33 S 16v Permanent 4 GMo

mt · Posted: Mon Jul 04, 2005 11:19 pm Post subject:

Well, the garage changed the feeder pipe and the oil leak was still there. £160 wasted.
But, i finally found the source of the leak tonight! The block is cracked on the distributor housing Sad

I'l probably put the dizzy back on tomorrow and take the car to a welder to find out if it can be repaired in situ, i can't afford to replace the block.