S3 BAM crankcase breather problems

[peejay01]

Hi gents,

I am having some issues with the breather system on my S3.

1) There was a lot of oil misting in around the breather and vacuum lines the inlet manifold.
2) I had the issue of the crankcase not being under vacuum. (shown by loosening oil cap and it being bounced around by the blow-by.

I know most of you guys that read this will say "catch can- simples" but I wanted to keep it OEM (ish) and now I've spent the money I am determined to get it to work. In short I replaced all of the breather system (silicon tubes from creation motorsport, hockey puck, PCV valve, jet suction pump, breather elbow near oil filter, brake servo pipes,checked all hard plastics for splits). I got rid of the misting which I think may have been due to a broken dipstick holder.

The crankcase is still not under vacuum after all of this!! I tried to trace back all of the connections and made sure they were tight and to see where I may be losing vaccum. When I remove the y shape breather from the block (still connected to hockey puck and the rest of PCV system) it is actually blowing out fumes rather than being under vacuum (which I assume is the correct mode of operation). I cant figure out where this positive pressure is coming from.

I have attached pics of the breather system before and after with the replacement parts in place- maybe it's something simple that I am missing...

Any help would be appreciated!

 

[NickVC]

piston rings?

 

[SamHendry]

I wonder is blowby pressure volume greater than capacity of air being extracted by the engine.? Considering the engine is sucking most of its air through the air filter, how much vac does the crankcase even get.?

When I remove the y shape breather from the block (still connected to hockey puck and the rest of PCV system) it is actually blowing out fumes rather than being under vacuum (which I assume is the correct mode of operation). I cant figure out where this positive pressure is coming from.

Positive pressure will be from the outlet on the oil filter housing

 

[desertstorm]

As above do a compression test on it. How many miles has it done? The crankcase breather system can only cope with so much blow by.

 

[peejay01]

As above do a compression test on it. How many miles has it done? The crankcase breather system can only cope with so much blow by.

Will do a compression test on it then. It's got 130k on the clock. Rings sound like an expensive job. Engine out for this?

 

[peejay01]

Thanks for all of replies BTW. Much appreciated!

 

[Tj 0785]

Expensive yeah would need a rebuild rings have gone on mine been quoted £3k to rebuild it and that’s only the bottom end not including any head work.

Will do a compression test on it then. It's got 130k on the clock. Rings sound like an expensive job. Engine out for this?

 

[hydro s3]

That does sound very expsensive just to do the rings tj0785. Have you shopped around and that's the best you can get it done.

 

[Tj 0785]

Locally yeah that’s with awesome gti who have a very good reputation not as good as badger5’s though.I think it was £2800 inc vat that was with a rebore riffle drilled rods, wossener pistons oil pump and so on I did get a full itemised quote

Found the quote
I hope it’s not your pistons rings,we’ve kind of jumped to worse case scenario. when I got mine compression tested cylinder 1 was stupidly low and 2,3,4 were all where they should be

 

[peejay01]

@TJ0785 did they advise you to do rods and pistons too? I thought you could do the rings without doing that. Well at least without doing the rods? Are you going bigger turbo at some stage?

I've had trouble getting the car to start first time recently. Could this be a sign of the rings going?

Recently replaced the fuel pump which remedied this for a while - think there is something up with the pump- either the level sensor or secondary pump transfer from other side of tank as sometimes the fuel gauge will move up and down randomly.

I suppose I better bite the bullet and get the car looked at. Hate handing it in to the garage as it feels like defeat but these guys do this day in/out.

 

[peejay01]

Just remembered I had oil in and around the sparkplug of cylinder 1 last time I changed but had read that this may have been the rocker cover gasket so replaced that and the half moon seal too a month ago. Maybe another sign of ring gone...

 

[Tj 0785]

Upgraded rods were because I plan on going hybrid or big turbo but need oversize pistons as The bores has worn so it need re boring plus I don’t see the point in only doing half the rebuild

 

[hydro s3]

Are you doing valves and cam springs while you have the engine open. Since you're going hybrid is that not advisable aswell?

 

[Tj 0785]

Yeah probably will do yeah but nothing happening till next year.

Sorry prejay kinda hi jacking you thread

 

[hydro s3]

Sorry prejay never thougt.

 

[Stuart B]

let us know the outcome of your compression test, I have a leak down test kit to use, because mine has been doing the same after a low oil incident.

I am hoping an issue with the head so I can leave the engine in situ, but I fear piston / rings too for me. do you have smoke puffing out the dipstick too?

 

[peejay01]

No problem lads it's good to hear what other people are doing and issues they are having!

Stuart I will check the dipstick and let you know. I had a broken holder and there was smoke puffing out of it then so am assuming it will be the same now if I pull the dipstick.

Should I get a leakdown test or compression test done?

 

[Tj 0785]

No problem lads it's good to hear what other people are doing and issues they are having!

Stuart I will check the dipstick and let you know. I had a broken holder and there was smoke puffing out of it then so am assuming it will be the same now if I pull the dipstick.

Should I get a leakdown test or compression test done?

My dip stick would get pushed up if I booted the car,

 

[Stuart B]

No problem lads it's good to hear what other people are doing and issues they are having!

Stuart I will check the dipstick and let you know. I had a broken holder and there was smoke puffing out of it then so am assuming it will be the same now if I pull the dipstick.

Should I get a leakdown test or compression test done?

I think the common thing is to get a compression test first only because it is easy to do, a leak-down involves a compressor and adjusting the crank to get the piston and valves to the correct position to see if inlet valves, exhaust, rings, head gasket (cylinder-water, cylinder-oil, cylinder-cylinder, water-outside, oil-outside, water-oil) might be gone. I have the kit but have not done it as even with the results I think the head has to come off minimum.

example if the air is coming out the exhaust pipe - this might be valves not closing or a cylinder - cylinder HG fault.

I don't believe mine is a breather fault they are not blocked the engine puffs out of the cam cover breather, oil filter breather, dip stick and oil filler cap. I also have oil down the front of the engine.

 

[peejay01]

I think the common thing is to get a compression test first only because it is easy to do, a leak-down involves a compressor and adjusting the crank to get the piston and valves to the correct position to see if inlet valves, exhaust, rings, head gasket (cylinder-water, cylinder-oil, cylinder-cylinder, water-outside, oil-outside, water-oil) might be gone. I have the kit but have not done it as even with the results I think the head has to come off minimum.

example if the air is coming out the exhaust pipe - this might be valves not closing or a cylinder - cylinder HG fault.

I don't believe mine is a breather fault they are not blocked the engine puffs out of the cam cover breather, oil filter breather, dip stick and oil filler cap. I also have oil down the front of the engine.

I didn't realise there was that much involved in a lead-down test, I'll leave that to the garage if it needs to be done. I think I'll buy a compression tester then as it's about €50 here I'll be paying that at a minimum to get a garage to do it. Could come in handy in the future.

Is 140 PSI the lower limit? 10% between cylinders?

 

[Tj 0785]

Be careful with cheap tester been a few on here that have had false readings with them. Ideally you want to use one that you know is reading true A garage should have a decent one

 

[SamHendry]

I didn't realise there was that much involved in a lead-down test, I'll leave that to the garage if it needs to be done. I think I'll buy a compression tester then as it's about €50 here I'll be paying that at a minimum to get a garage to do it. Could come in handy in the future.

Is 140 PSI the lower limit? 10% between cylinders?

Quite right mate, the cost of getting a garage to do it is probably more than the tool itself, plus you get the experience and you can do much more thorough test and get feedback, repeat the test for accurate results,

 

[Stuart B]

make sure you pull the fuel pump fuse

I don't think it needs to be 140 - I thought they were 125 or so - these 1.8T's are supposed to be low compression.

 

[SamHendry]

make sure you pull the fuel pump fuse

I don't think it needs to be 140 - I thought they were 125 or so - these 1.8T's are supposed to be low compression.

125? That's a bit low mate. 170+ is what you would expect from a healthy engine. My 115k engine was 150psi before I rebuilt it, ran fine although did use oil.

 

[hydro s3]

I thought i had read it on here of the compression should be 170-190 for a good healthy engine.

 

[Stuart B]

ahh sorry, I miss-remembered people uploading their images.


From another forum testing a BAM
-------
I've done a bit of research and from what i can find is that it has a compression ratio of 8.9:1.

The compression pressure should be 17-20 times the ratio, so should be between 151.3psi and 178psi. With a maximum 10% tolerance between the cylinders. Therefore a 15-18psi difference maximum.

Can anyone confirm?
---------

 

[hydro s3]

This is of IanPG's thread after he had rebuilt his. So it seems 180 is the mark to go for.

 

[peejay01]

Thanks again gents. I've ordered the compression tester and am hoping to get time to test this weekend. I've got a suspicion that I am going to have low compression in cylinder 1.

The question is then do I want to rebuild the engine. An engine rebuild has been on my bucket list (I know-so boring!!) so I might end up buying another daily and keep the S3 for a rebuild and do it myself. I even bought this http://jazzpur.blogspot.ie/ a while back.

 

[SamHendry]

The question is then do I want to rebuild the engine. An engine rebuild has been on my bucket list (I know-so boring!!) so I might end up buying another daily and keep the S3 for a rebuild and do it myself. I even bought this http://jazzpur.blogspot.ie/ a while back.

Jazzpur.blogspot.ie 5 part guide really helped me do mine along other snippets on the Internet which helped.

Get stuck in mate have you thought about throwing a set of forged rods in while engine is all apart?

 

[peejay01]

Jazzpur.blogspot.ie 5 part guide really helped me do mine along other snippets on the Internet which helped.

Get stuck in mate have you thought about throwing a set of forged rods in while engine is all apart?

Oh yeah definitely man, I've thought about it a lot! If I'm rebuilding the engine I'm going to go new rods, pistons, big turbo etc. I know I'll be looking at putting at least 4-5k into the car but if I look at the fact I could have it for another 120k miles and I'll know how healthy the engine is it will be worth it!

Any links or other useful info that you used for your rebuild would be appreciated!

 

[desertstorm]

When I measured my 90K mile BAM engine got 1 cylinder at 180, 2 at 175 and 1 at 160. So 175-180 seems to be about as good as it gets. If I ever get around to putting rods in mine then I will investigate the 160psi on cylinder 1.

 

[Stuart B]

is cylinder 1 a weak point on this engine? I have had no end of trouble with coils, spark plugs and head damage on that cylinder and 2 posts on this page of iffy cylinder 1's?