ethan169

iTrader: (3)

Heres the car and short list of mods:
2003 Evo VIII 78k miles

Mods:
GSC S2 cams w/beehive springs and stock retainers
IX turbo
Megan SS O2 housing
Buschur TBE w/test pipe
Dry filter with MAF adapter stock intake tube
ETS V2 LICP
Hallman pro MBC
PTE 1000cc injectors

So for a while now ive been burning a little bit of oil. realistically about 1qt every 3k miles. I dont get a whole lot of smoke coming out of the exhaust but there is some. Im also not running a CAT so it stinks anyways.

When i do a boost leak test i do get pressure in the valve cover, and YES i am pressuring right at the turbo inlet. So my oil cap will **** out some of the pressure. Iv reinforced the seal of the cap so it doesn't really **** out but it is still pressurized. I also get pressure coming out of the hose that goes from the front of the valve cover to the intake tube. I plug this off as well during a pressure test to keep the air from pissing out. I have check my PCV valve and it was fine but i replaced it with a genuine OEM mitsu one anyway. Cheap insurance. Same problem.

Ive done a compression test about two weeks ago and these were the numbers.
#1 = 171
#2 = 180
#3 = 181
#4 = 174
This was done on a bearly warm motor. It was basically started to be pulled into the garage and then turned off. So i assume these would be the worst case numbers as the rings are barely lubed...
Seems ok to me. Especially for almost 80k miles....

So because of the burning of oil and the pressure in the valve cover does this point to leaking valve seals?

Id like to do a leak down test but do not have a tester. Would this pinpoint the problem?

Would this cause any difficulty in tuning? Im having a hard time with inconsistent knock. But i also have a feeling that my GSC S2's and beehive springs are causing some valve train noise adding to the knock issues.

Sometimes i will have a clean run that will pull hard. Others ill have a run with knock here and there. Timing is not too aggressive either.

Im more concerned about burning oil as its a pain to keep track of and i dont want to run it dry.

Thanks for any info,

Ethan

motocooney

iTrader: (6)

I think it's normal to have pressure blow out the oil cap IF...you're not at TDC and testing on a cold engine. Also, I don't believe you're supposed to block the breather port on the drives side of the valve cover.

I recently had the same problem when performing a boost leak test. Read up on a few threads and found a good way to find TDC. I retested and had no pressure coming out of the oil cap.

There is a small notch on the crank pulley and a "T" on the lower timing cover. If you line these up manually with a 1/2" drive ratchet/breaker bar on the pulley you will be at TDC.

Also, wouldn't a compression test reveal leaking valve seals?

You're compression is pretty good for a engine with that many miles. The numbers aren't perfectly consistant. But they're fine. My car has about the same mileage and mine are 172ish across.

My03evo

iTrader: (1)

I wouldnt worry about those numbers, theyre not bad especially for those numbers. When you did the compression test you had the throttle open right? Alot of people forget to do it. and I assume you had the plugs out so the engine turns over easier and quicker and reduce slow cranking with a weaker battery. If youre concerned I would do a leakdown test, I think harbor freight has a cheap setup or you can make one for even cheaper and it will tell you alot. Also what oil are you running brand and weight?

awdordie

iTrader: (1)

Have u checked the turbo for shaft play? How many miles were on it when you got it and how many have u put on it since then? Or did u buy it new?

Evoryder

iTrader: (55)

You're not testing properly. You probably capped the breather hose off.

ethan169

iTrader: (3)

Interesting.....

I guess since the breather on the drivers side was always leaking a little bit of air i blocked it off so i could see if the system would hold pressure. Iv'e never actually tried putting the engine at TDC to do the test though. Maybe thats the problem.

As far as turbo shaft play there is none. The turbo supposedly had 12k miles on it when i installed it. That was 10k miles ago MAX. So its really hard to say because there is no way to really know how many miles were on it originally. It did look very clean and had now axial or radial play whatsoever. My stock VIII turbo is tight as a can be as well and that one was pulled off at 68-70k miles on it. Same problem with both turbos so i dont think its a turbo issue....

As far as the compression test. I do know that your supposed to keep the throttle open and I did have all plugs out. For some reason now im doubting myself and I feel like maybe i forgot to hold the throttle open. What kind of change would that make? Ill redo the test hopefully tonight.

Where else could me oil be getting burned at? Its annoying.....

thanks for the response guys

barneyb

The story that always accompanies pressure testing is that you turn the engine to TDC and all the valves magically close. Is that true? You bought an aftermarket cam. It should have come with literature describing lift and duration. Figure it out.

ethan169

iTrader: (3)

Yes I understand that the overlap and large lift the S2's have would make it difficult to have a completely sealed system. However i dont understand how this would affect the seal of the valve. Meaning how is the valve cover pressurized when a valve opens? Isnt the stem sealed? I understand that air can escape out of the exhaust etc during a pressure test. but not into the upper section of the head? Maybe i dont fully understand how everything works in the head.

More importantly how is the oil getting from the valve cover area into the combustions chamber? Short of a physical hole what areas are possible failures? Valve stem seals, piston rings? what else?

Thanks for your input

barneyb

If any intake valves are cracked open, the air pressure you apply for the test is in the cylinder. Piston rings are meant to hold pressure for the instant it takes to compress and ignite the mixture, not hold against steady pressure. Air is going to leak slowly into the crankcase. If you insert a ratchet wrench into the end of the crankshaft and rotate it you can hear and feel the air leaking by the rings.

To test for bad valve seals drive the car until the engine is completely warmed up. Then park and let it sit for half an hour. Start the engine and watch the rear view mirror. If you see a cloud of smoke the clears up after a few seconds your valve seals are bad.

joey110892

iTrader: (3)

i recently had to fix my valve seals, the car only smoked when it was idleing

ethan169

iTrader: (3)

Im not sure why i never responded to the last comment by barneyb. I tried this driving for a good 30 min. Coming back like 30 min later and starting the car up. It did seem to smoke more so i suspected valve STEM seals.

I purchased new ones and decided to dig into it. Even though I was nervous about changing them with the head still on the car. When I installed my cams I used an on car valve spring compressor and a pressure tester to pressurize the cylinder. Got to retainers off and all was good. Moved to the intake side and DING! The valve dropped into the chamber . It helps to check and see if there is a shrater valve in the pressure tester first!

Anyway Once i even removed just my valve cover it was clear where the problem was. Or at least part of it. My valve stem seals were completely trash. The end "boot" with the little spring around it where the seal is was all torn up on almost all 16. And the spring was either stretched out or completely gone on about 8 or so as well.

Its a cheap fix but time consuming considering what has to be removed to properly change them out.

Today no smoke or oil burning what so ever. Not to see how long they last. I have a feeling the stock retainers with these cams (S2's) are beating on the tops of the seal.

newbieEVO8

iTrader: (9)

Those beehive springs are they a dual spring set up where you have an inner spring and an outer spring?

If so, the inner spring is going to beat the heck out of your valve stem seals and you will be doing this again.

Some one makes a smaller outer diameter seal that would fix this issue.

ethan169

iTrader: (3)

They are single spring setup. And the new seals I put on are the supertech ones that are supposedly smaller diameter as well and work with dual setups. So hopefully I wont be tearing anything apart again until I feel like doing another Tbelt change.

Thanks for the heads up though!

newbieEVO8

iTrader: (9)

That's good.