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Engine Specific Info and Questions => IDI Engine => Topic started by: jlpst94 on July 19, 2013, 09:08:00 am
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79 rabbit with 300-325 psi in all cylinders and even taking off the breather hoses it still burns oil like crazy. The head was machined and I used ARP studs and new head gasket torqued to 80lbs.
I know it has blow by and I was gonna make a catch can but even with the breather lines un hooked and not blowing into the intake and cam cover it still burns oil like crazy.
Do these engines need more than 300psi to keep the oil under the rings?
Any other ideas? Thanks guys
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That's if you still have rings.
- new engine 493 psi
- lower limit 412 psi
- no more than 73 psi difference between cylinders
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I have a 1.6 and my arp studs were 125 pounds are the 1.5's different?
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How much oil loss?
How much smoke?
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I have a 1.6 and my arp studs were 125 pounds are the 1.5's different?
125 on my ARP studs as well (ARP spec) - 12 mm and 1.9
Not sure how that would affect oil pressure or blow-by though.
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all 1.5 are 11mm studs
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Get out the breaker bar and torque wrench your oil consumption is about to go way down and I bet you even get some additional PSI in the cylinders. 80 lbs? That isn't even close to the spec 90 and If you haven't tightened them down after the initial running of about 1000 miles I am going to guess you are no longer close to the initial 80 you had.
Put a wrench on it.
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Hrmmm... I'm not convinced compression is getting out the head gasket, but a nip-up can't hurt.
I rekon it's rings, but how much loss is still unknown.
"Burning oil like crazy" with the vent tubes off sounds like mistaking smokey retarded timing for "oil burning".
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Arp 11mm head studs dont require retorque and 80lbs is the torque it said to use.
The pump timing was set with a dial gauge. Its also bluish tint so its not fuel.
Smoking like crazy means a ton of smoke. Like go i go up the road , turn around and come back, and I can still see a smoke screen all over the place.
Ive read on here that a 1.5 needs 500psi in all cylinders but I dont have any facts on that.
On my 1.6's. 300psi runs strong and no smoke what so ever.
The only thing Ive considred is the head gasket I bought. Is it possible that I recieved a 1.6 gasket and by putting that on a 1.5 ive somehow blocked off an oil hole? Im not sure how that works or if its possible.
I do remember a hole in the front of the gasket with a rubber gasket though so I think it was correct
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Sure your gauge is good? 300 is only 60% of what is should have.
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Max of 483 is 1.6L per Bentley I think. 500 for 1.5L???? hmm never read that.
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Gauge is good. It seems like it has to be oil getting past the rings but I didnt think it was possible with 300psi compression. I wouldnt have spent the money to have the head machined if I knew it was gonna do this!!
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You have done a new gasket, studs and machined head.
I assume you replaced the valve guides or at least replaced the seals? Did you check the guides?
How about the rings - did you replace them?
My guess is valve seals - The compression would be decent but oil could dump past the seals if they are damaged or worn out.
When I re-did my 1.9 I really had to be careful sliding the seals/valves over each other. I used a plastic straw to keep the stem grooves from screwing up the seal lips.
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The shop that machined the head did the valves and seals. It's a reputable place that has done a few 1.6 and 1.9 heads for me. I did not put new rings in because I thought 300-325 per hole was a decent number.
Like I said I drive a 1.6TD daily with those numbers and it runs great.
If I don't get any more opinions maybe Ill call the shop and double check.
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The shop that machined the head did the valves and seals. It's a reputable place that has done a few 1.6 and 1.9 heads for me. I did not put new rings in because I thought 300-325 per hole was a decent number.
Like I said I drive a 1.6TD daily with those numbers and it runs great.
If I don't get any more opinions maybe Ill call the shop and double check.
Based on your experience then, compression isn't an issue - yet that seems to be your focus.
I'd be looking at valve guides and seals. I get that the shop is reputable and I don't blame you for figuring they did things properly, but that doesn't mean there were no errors on the valve work - they are human after all :)
Not too familiar with the 1.6 [edit - 1.5] but the 1.9 had two valve stem diameters yet the seals for either would snap into place on the guides. In other words, you could install 8 mm seals over 7 mm stems - that would "feel" ok during the install till you ran it and it smoked like crazy.
Not sure what a phone call could provide unless they can give you the part numbers of the new seals they installed - along with the old seals as well.
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If it was smoking before the head and still is now then it is the bottom. A ton of times you seal up the top and it makes it worse as it is tight and now the bottom still isn't tight so the oil burns worse than before. Glad your experience worked at 300 but that is horrible compression for a 23:1 diesel. I have had similar experience as you with 350psi and had to rebuild.
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Diesels don't care what oil, they burn it all unless timing is off. Sooty/dark is overfueling, white/blue/grey is retarded timing.
Timing with a dial gauge is only half the story - Injector break pressure is the other half.
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Diesels don't care what oil, they burn it all unless timing is off. Sooty/dark is overfueling, white/blue/grey is retarded timing.
Timing with a dial gauge is only half the story - Injector break pressure is the other half.
Precisely. lol
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My Dads telling me the compression ring can he good but the oil ring can be shot.
I ordered new rings today and i'm gonna see what happens.
As for the question about diesels burning anything and its the injectors....... The injectors all pop at right around 1800. Also the throttle runs away slightly so I know its oil. And its blue smoke.
Thanks for all of the opinions guys.
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Fair enough, if the engine is on the verge of runaway, I'd go for rings.
It could be instructive to advance the timing "by ear" to see the results. I can easily imagine that low compression will delay the start of combustion, so advancing the timing might be one way to postpone a ring-job (but come winter, that might bite ya).