2.3L ('83-'97) Overly High PCV Pressure

[ylidk]

Performed a compression test after the test drive to check the condition of the engine:

1 - 120 psi
2 - 110 psi
3 - 110 psi
4 - 120 psi

I believe 120 psi is healthy compression for the 2.3 Lima, correct? This is a turbocharged engine so I'm not sure if the compression in each cylinder will be significantly lower than the healthy value in a N/A motor. If 120 is acceptable then the engine seems fine. Cylinders 2 & 3 are slightly lower but so cylinders are within 10% of each other. If thats healthy psi for a turbo motor then blow-by doesn't seem excessive. Can't say for sure when under boost I suppose?

 

[scotts90ranger]

I don't remember checking compression on mine, not sure on what it should be, I probably knew at one point... but at 8:1 it's not a lot but I would have figured closer to 150...

I'm sure you're way over thinking it, there's gotta be something, my '90 is in my shop, I'll try to get out shortly and see what the heck I did...

 

[scotts90ranger]

I went and looked what I have and apparently I have zero shenanigans' anymore... the PCV is just kinda chilling out without any clamps other than the one at the intake manifold end, the factory breather filter is sitting on the valve cover (I might have stuck it on with ultra black, don't remember, didn't pull on it) and the little 1/4" hose leading from it goes to the inlet of the turbo in a plain fitting... I took pictures but it's just really the stock setup.

Either the piston rings aren't breaking in very well or the first and second ring are backwards or something odd... If I get a wild hair I'll try to run compression on a cylinder for giggles, I'm not a big fan of how I have it sitting on a jack stand right now so I'm not playing too much... might not have a chance until next week but I'll see what I can do.

A leak down test would tell more.

 

[ylidk]

I'm glad you mentioned the compression ratio there. Based on 8.0:1 without boost expected compression should be about 118 PSI (8.0 * 14.7PSI), so that makes me feel better about that at least. And I agree, I 've got to be way over thinking this, I just don't know what I missed. Would a clogged oil separator cause these issues? Oil just not able to drain as fast as it is being pumped? Using a standard volume Melling pump, not high volume.

I will run a leak down test on the truck sometime this week when I can. Supposed to be rainy all week and the truck isn't in the garage.

 

[superj]

does your valve cover have no baffling inside to help deter the oil from spraying out? i would say that if there is no baffling, even just the oil being splashed/sprayed onto the rockers will get thrown out the pcv some amount.

 

[scotts90ranger]

Assuming the stock aluminum turbo valve cover, there's no baffle on the vent side just the oil fill side (some oil caps had a hose out the top for crank vent)

 

[ylidk]

I do have the stock turbo valve cover, but I think there's a simple baffle to help deal with oil splatter. Just a sheet of metal to make the oil have to go around. Picture of the engine when I first picked it up is attached to show the style of valve cover. I don't think I have any pictures of the inside of the valve cover.

Even if it doesn't have a battle, it isn't just a bit of oil spray I'm dealing with. This truck is shooting out over a quart of oil through that vent over the course of a few short test drives. The puddle under my truck will devastate ecosystems

I have a spare "fuel injection turbo" valve cover that I may try swapping on after I get it painted, I just need an intake riser. This one definitely has a baffle along with a smaller size of vent hole so it may help.

 

[superj]

since it seems to be the thought that rings are not fully seted yet, can you home make a hose form the pcv hole to the oil fill hole so the oil gets dumped back into the system and run it like that for a while till the rings seat?

 

[superj]

at least it will keep you from having to fill the oil every time you turn the truck on and keep your driveway from being an epa site

 

[ylidk]

since it seems to be the thought that rings are not fully seted yet, can you home make a hose form the pcv hole to the oil fill hole so the oil gets dumped back into the system and run it like that for a while till the rings seat?

Yeah I'm thinking something like this is needed. It isn't in any of the pictures, but it does have a hose right now to a catch can, but the oil actually sprays out from between the valve cover grommet and the 90 degree elbow adapter, so I'll try sealing that with some tape or rtv or something

A leak down test would tell more.

I ran a (cold) leakdown test using a tester I have had for a while. No idea how accurate the gauge on it is, but it all cylinders were relatively within range of each other:

1: 30%
2: 33%
3: 35%
4: 25%

These numbers seem high, but then again the gauge says up to 40% leakage is in the green. I intend to do another leakdown test with the engine hot and with a rented unit to cross reference

 

[scotts90ranger]

The leakdown testers we have at work I trust more than most of the cheap options... the ones at work you air up to 100psi and read the differential pressure between the gauges. I bought a ~30 one from Amazon and I'm pretty sure it airs up to like 25psi which sounds sketchier to me...

On the testers at work (MAC and Snap On) I think they say up to 15% is ok if I remember right...

I did have a lot of blowby until the rings seated, to the point I had one of the oil fill caps with a hose barb and had that leading into a quart oil jug which never seemed to fill up but did gain some... then the leaks started, the wastegate linkage wore a hole in the drainback tube, cam bolt threads weren't sealed (that one made a MESS) and I think that's most of them...

 

[ylidk]

Yeah I think I have the same style or similar Amazon tester to the one that you used. It says provide 7-100 PSI and then open until the needle lines up with the 0PSI mark. That usually happens at a relatively low PSI. After connecting the gauge to the cylinders that gauge jumps up (down?) from the 0psi calibration mark to the leakdown psi. If I bump the gauge it will jump to like 80% so it's definitely not the highest quality.

That being said, I took it for a relatively long test drive (1 hour round trip) to sell something on marketplace. I disconnected the intercooler tubes so the turbo vented to free air and ran it N/A. I did not see much smoke with this setup, so that's a good sign. There was a bit on the first half of the drive until I realized that where I moved the filter to was starting to melt a bit against the turbo housing.

On the way back it developed a misfire on cylinder 2, haven't tracked down why yet, but opted to come straight home instead of grabbing the rental tool because of that. Did a leakdown test on the hot engine and the results are essentially the same as before. Eventually I'll get the rental tool and see what the difference is on the cold engine and interpolate the difference.

Not sure why the engine developed a misfire, but I replaced the plugs and wires earlier today and gapped them a lot tighter (0.024") to see if they can hold up to boost better than at 0.028", where it seemed to be unable to keep up at high rpm under boost, so that might have something to do with it.

 

[ylidk]

So, another update. I went out and bought a leakdown test gauge set from harbor freight, that uses the two gauges at 100 PSI and the difference is the leakdown percent as previously mentioned. I was able to get a couple of possibly good readings, but when the cylinder was on TDC and I started to add pressure it would actually push the piston down and start turning the engine, even with the truck in gear and parking brake on. It was enough to get the truck to push forward until it finally wasn't able to push the piston down any more. There were a couple of times I managed to get readings without it pushing the engine down by holding the crankshaft in place with a breaker bar.

I only did this on cylinders 1 and 2 before I called the shop that did the work to see if they'd take a look at it this week to verify that it's getting past the rings and see what they say. Starting with the gauges unhooked from the cylinder and 100 PSI supplied, cylinder 1 read 85 on the first gauge and 66 on the side going to the cylinders (22% leak) and cylinder 2 read 96 in 82 out (14.5% leak). I started with cylinder 2 and stopped since cylinder 1 was above that 15% acceptable mentioned in a previous post. I could feel and hear the air coming out of the valve cover holes and the oil dipstick tube. Not sure if the issue is actually because it isn't broken in yet or not but I really don't know how long I should sit and deal with it assuming it'll break in eventually before deciding to take it back apart for bad rings, etc.

 

[scotts90ranger]

That brings up a couple questions really, if it was truly at TDC it wouldn't fight, so has the balancer spun or were you just off a few degrees? If the balancer spun your timing is also off...

Ok, aside from that, do you know if they used iron rings or molly rings? Iron rings break in faster but are easier on the cylinder walls, molly rings take longer to break in and are hard on the cylinder walls...

Kinda sounds like you're onto something, and also good to know on the HFT leakdown tester, I'll probably pick one up, I have a camry engine I want to check into more, the low pressure leakdown tester said one cylinder was full dead...

 

[ylidk]

I bought Wiseco 3820H rings, which are iron rings with a plasma moly facing on the top ring. https://www.summitracing.com/parts/WIS-3820H

I probably just didn't have the engine rotated properly to TDC, I was basing it off of sight of the piston through the spark plug hole. This engine doesn't have a harmonic balancer, so if the timing is off I must have put the belt on a tooth off. It runs smoothly enough that I don't think the timing is off a whole tooth though.

Likely the final update until the engine comes back and I can say the problem is fixed for good: I took the truck to the engine builder today so he could take a look and immediately after seeing the amount of smoke from the oil just on the short drive over he was saying there is definitely a ring issue, it was way too much blow-by for break in, so he'll warrant that fix and order a brand of rings he trusts more, I think it was Total Seal rings that he said; I just have to take the engine out and bring it in to him. Said it's the first engine in over 30 years that he's had ring issues with, just my luck

the low pressure leakdown tester said one cylinder was full dead...

The nice thing about the low pressure tester in my experience is that you can just smack the gauge until it gives you a reading you like