White smoke, issues, out of ideas!

OK, got my diesel compression tester today and the results are in. All 4 cylinders came in right at 24 bar, or about 350 psi. All 4 were right there at the same reading. I got a WinMax tester from Amazon. Pretty cheap but it had good reviews.

ClemXP said:

OK, got my diesel compression tester today and the results are in. All 4 cylinders came in right at 24 bar, or about 350 psi. All 4 were right there at the same reading. I got a WinMax tester from Amazon. Pretty cheap but it had good reviews.

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Cold motor or hot?

have you checked "injection timing (actual)" under full load

Cold engine

That is on the low side of the range, but given they were all the same, I'd say you are probably OK there. However, if the oil pump is stuck and hyperextending the lifters, the engine may actually have to start and run in order to make that happen. In which case, a cranking compression test will not necessarily reveal anything. Unfortunately.

I know from my experiences with that happening, the deal was, the engine would start up cold like normal, and would IDLE alright, but if you raised the RPMs to around 2k or so, it would start missing (and in the case of the diesels I have seen with this issue, start smoking with unburnt bluish-white fuel smell clouds) until the oil got just warm enough that the pressure dropped back off a bit but was still sky high. The couple I checked with a gauge were able to peg it, and it was a 300 psi ATF pressure gauge. That's crazy high oil pressure.

Other possibility is the pressure valve(s) in the injection pump, the four that screw into the head that the delivery pipes attach to... but I would not think that very likely, and I would think they would stay stuck no matter what.

I doubt it is the IP since I swapped that out with one from a wrecked alh and got the same exact issues. Where is the port to test oil pressure? What is the range for oil pressure, and is high pressure a sure sign of a bad oil pump? Other possibilities?
Is there a visual way to check the lifters with the valve cover off? I am not seeing much about them in the Bentley manual. If so, what do I look for?
It looks like I can change out the oil pump just by removing the oil pan and bolting on a new one. I was afraid it would involve tearing it down more than that, but it looks relatively simple.
Thanks for all the help. I am hoping to be getting closer to figuring this out!!!

You check the oil pressure at the port where the switch screws in, on the side of the oil filter housing. 2.5 bar @ 2000 RPM is the spec, with a MAXIMUM of 7 bar, so about 40 to 100 psi.

Easy to swap the oil pump, but you will have to remove the Torx screw that holds the sprocket on the front, and hold the chain tensioner spring up (which is behind the front sealing flange). Not hard.

Tested oil pressure and it is right around 1 bar at idle and 2.5 at 2000 RPM. I can get it up close to 75 when I rev the engine to about 3000 RPM with no load. This is with the engine hot. I am letting it cool down now and I can take a cold reading if that is helpful.

Also, I tested compression just on Cyl 1 with the engine hot, and it was the same as cold, about 350 psi

Leave the oil pressure gauge hooked up, and check it after a cold start, although it does not sound like that is your problem. Usually when they stick, they stay stuck, just that the problem is only noticeable when the engine is cold.

Let it cool down and started it up - oil pressure is above 50psi, pushing 60. Definitely higher cold.

Am I on global ignore or what?

I drove around and watched the "Start of Injection Timing" specified and actual. Car was at operating temp. Timing is set right in spec, not advanced or anything.
I'm not really sure what I am looking for. It ranged from as high as 7.7 BTDC while under heavy load to 1.0 ATDC while decelerating or driving in low RPMs in 2nd gear. Mostly both numbers were within 0.2 of each other, with some exceptions. Again, I'm not really sure what I am looking for.

I started the car with the oil pressure tester attached and this time it was around 75 psi cold. Does this condemn the oil pump? Is there a way to test the pump? Could this be a symptom and not the cause?

Edit: I read the section on lifters. Is this my next test? If the oil pump is acting up and there is an issue with the lifters, is that likely the whole problem, or could it have caused other issues to the valves? I'm just wondering if new lifters and new oil pump are all I need, or is there even more rabbit hole extending ahead of me...

Thanks for all the help once again! I love learning more about these cars and I get so many great opportunities when they aren't running right!

ClemXP said:

I drove around and watched the "Start of Injection Timing" specified and actual. Car was at operating temp. Timing is set right in spec, not advanced or anything.
I'm not really sure what I am looking for. It ranged from as high as 7.7 BTDC while under heavy load to 1.0 ATDC while decelerating or driving in low RPMs in 2nd gear. Mostly both numbers were within 0.2 of each other, with some exceptions. Again, I'm not really sure what I am looking for.

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[486] said:

plugged fuel filter?

you get too much vacuum on the inlet of the pump and it'll lose all timing advance. IIRC stock base pump timing is like 3 degrees after TDC so def. white smoke and no power city

if the filter doesn't get it, try a separate fuel can plumbed into the filter's lines to the tank

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Ok, tried a couple things and the same issue.
Removed the valve cover and tried to check the lifters per Bentley. I depressed the lifters with a wooden wedge and I couldn't get a 0.008 feeler gauge, or even a 0.003 feeler gauge, in between there and the cams. On any of the ones I tried. Not sure what this means.
I then put a fuel line directly from a can of diesel to the injection pump inlet. I didnt drive around this way, but after getting it primed and letting it cool down, the first start was longer than it should be and there was white smoke. So I don't think it's a clogged filter. Also, this is a new filter with less than 500 miles on it.
Any other thoughts? Could it be the oil pump? How can I know for sure? If there is something serious wrong, like with a valve or something requiring a tear down of the head, I don't want to waste the time and money on an oil pump.
Thanks guys

camshaft timing was set with timing mark on flywheel (not balancer) and something jammed in the slot in the back of the cam, correct?

Yeah, When I did the TB I used metalnerd tools. I locked the cam at the vac pump side, used the timing mark on the flywheel, locked the crank and IP. Also verified everything with VAG COM. I've swapped the IP and checked the mechanical timing multiple times; everything is lining up. I always set the final time with the VAG COM by adjusting the 3 nuts on the IP.

ClemXP said:

Let it cool down and started it up - oil pressure is above 50psi, pushing 60. Definitely higher cold.

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60 psi cold is fine. The regulator is not stuck.

Thanks Genesis. That answers one of my questions. Are we down to lifters and/or a valve?
Could I have a stuck lifter? Any way to check that? Again, i tried to measure clearance between lifters and cam lobes (upward position, of course) and got nothing. Does anybody have experience measuring lifter clearance that could shed some light on this?

Doesn't sound like the oil pressure is the problem, you've ruled that out.

There is no "clearance" on a hydraulic lifter, the whole purpose of them is to be dynamic and keep the follower/cam/valve clearance at zero all the time. Hence no need for valve adjustments.

No abnormal oil consumption from the engine? Do you have another set of injectors just to try? I really doubt it is that, but just to rule that out. I'd also thought of perhaps somehow the anti-shudder valve was randomly shutting (no idea why) but your symptom seems too predictable for that.

I do not have another set of injectors to try. It was doing this before I got the new nozzles and calibration; I thought that was the problem and threw parts at it, thinking I would be doing them anyway. No abnormal oil consumption noted. I will drive it some more and keep an eye on that. I don't think it is the ASV. It moves freely and I've swapped EGR/ASV with a parts engine I have and no change.
I understand now on the lifter clearance. Bentley says 0.008 MAXIMUM, and I thought that meant there should be some. In that case, lifters seem fine. Although, could one be sticking?
Sounds like the next thing to do is a leak down test. I need to either buy a tester or find a buddy with one.
Any other thoughts?
One more thing: if the case is that a chunk of coke got in at the intake when I cleaned and replaced the manifold, what would that mean? If it was stuck there around the valve, wouldn't the problem either work itself out, or always be there? It's just weird how this is intermittent and predictable. Once it gets to that powerband under full load and blows the smoke and shudders it's good until it sits/cools down a while.
It's also not completely an operating temp thing. If I get the car warm without any hard driving it still needs to do this thing once, although it does seem a little less extreme when the car isn't still warming up.

Fuel filter

It's not the fuel filter. I just changed it out and it's the same thing.
Could it be a clogged catalytic converter??? Would that make sense? I can try unbolting the exhaust tonight after the car cools down.

Could be,,, fuel temp sensor

I don't think its the fuel temp sensor. I swapped IPs and I'm getting the same exact problem. I'm going to dig into the turbo some more to make sure there are no leaks and that it is properly boosting when cold.

While you are in the turbo, check and make sure your nozzle ring isn't worn where the nozzles and actuator contact. Also contact area on the cartridge.