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Problems/Service/RepairsIf you have a problem with your HHR, want a tip on repairing or performing a particular service to you HHR here is the place to post!
The wet test actually eliminates the valves, a bit of oil won’t seal up the valves, but it will seal the piston rings.
a Seafoam bath for the rings is a great idea, might just work , if you are thinking of taking the head off then blast the valves while the head is disassembled.
We have seen many times , Members go thru this procedure and still end up ordering from ZZP.
its not 100% just 99&44/100% , the resulting solution.
The reason I suggest complete engine and turbo is , then everything is new, assembled for you and there’s a warranty, unlike when Inrip an engine apart, replace most of the parts and the one I consider serviceable, well there’s the chance for a Homer moment!!
like spliting the block and removing the crankshaft and main bearings, filings from the oil pump.
I ran the dry and wet tests on all cylinders several times. So there's no issue there.
Perhaps there is a piston problem that I can't see yet, but I'm going to try everything else before scrapping the engine.
I'd like to ask more about the walnut blast...
I'm assuming the valve stays closed while blasting. That said, how does walnut blast cleaning the thin face that mates and seals against the head?
What about the exhaust valves? Are there concerns about them needing blasted?
Is microscopic walnut media left inside going to hurt the engine?
You're right, the blast doesn't clean the mating surfaces very well. After the blast, I soaked the area in berrimans, then opened the valves and brushed them.
There's a tutorial or 2 in the how-to library. Mine has a link to the other.
Yes, thanks. I read @RJ_RS_SS_350's writeup thoroughly. And I'm hopeful because his/her writeup also mentioned compression leakage into the crankcase, like me. So perhaps there's still hope for my engine; I'm not giving up on it that easily.
My plan this weekend is to take the intake and fuel injectors off. I won't do the media blast, but will inspect the intake ports and also swap #4 injector to another cylinder. Then I'll drive it a week to see if the code moves and thus pointing to an injector problem. I'll then make plans to take it apart again to replace the bad injector (if the code moved) and also do the media blast. I know it's a two-stage process, but I want assurance of what the actual problem is for #4. This weekend, I'll probably also do the leakdown test too, just to get a more thorough assessment of the engine's condition.
My next question...I viewed @cannuck's writeup here and watched his YouTube videos. One thing that wasn't clear to me...I'm buying parts for this weekend's work, but can't tell if the fuel line from the HPFP to the fuel rail has O-rings or is a metal-to-metal compression fit. Does anybody know?
Not understanding your logic of thinking it's an injector problem. The compression test clearly shows that you've got a compression issue on #4.
Maybe I'm reading and interpreting your posts wrong.
To say #4 has a piston ring problem negates the fact that all 4 cylinders jumped relatively equally in pressure with wet test. If cylinders 1-3 have good rings, I would not have expected them to jump much from their "dry" compression test results. So I then conclude that the piston ring condition of all 4 cylinders may be fairly equal. Nevertheless, I'm still not jumping to conclusions and scrapping an engine, without knowing I've checked every single thing to have complete assurance it is scrap. You folks are great and have a wealth of knowledge that I'm grateful to learn from. But if I could kindly share some candid feedback, you're also good at unnecessarily inciting fear and worry into a situation, forecasting the worst-case scenario, without checking the issue from every single angle. You folks frame this like it's changing a pair of socks and something that can be done on a whim with little setback. But the fact is, an engine swap is a major project and tons of $$$. So whether we agree on the compression test results or not doesn't matter at this point. I will leave "no stone unturned" before I make such a huge decision to scrap the engine. Any good mechanic would do that when faced with something that had high stakes.
If anyone can kindly share insight about the fuel line from the HPFP to the fuel rail, I'd be very grateful. I'm curious if it has O-rings or if it is metal-to-metal compression.
I don't yet have a good answer for why #4 dry produced lower "dry" compression results, but I don't believe it's the piston rings based on my statements that I provided earlier in this thread. In fact, despite the dry compression results, I'm still willing to believe that #4 may run fine if some other issue didn't also exist in the cylinder (e.g., bad fuel injector or gummed up valves, seating poorly). In other words, I believe several issues may exist in this situation and the lower dry compression may not be the primary culprit. And I believe that if those other issues are repaired, then #4 may run just fine for many more miles with no issue, because aside from a little cold startup sputtering, it runs like a champ.
The only piece of the puzzle we currently see is a set of compression results that seem to indicate a dead engine. I plan to open it up for inspection this weekend, as well as perform a leakdown test that will help shine more light on my hypotheses.
Again all of this is just a guess based on my conclusions of what I believe the compression test told me. You can say I'm in denial and I'd be fine with that. You can all laugh at me later if I find the engine is scrap and I'd be fine with that. But I'm not scrapping it without having checked everything; the stakes are simply too high. I worked on cars/engines since before I learned to tie my shoes (approaching 40yrs) and I've seen some of the strangest things happen. Something weird like this would not amaze me the least bit.
You are mis interpreting what the wet test does.
A. the dry test tells you which cylinder has a problem
B. the wet testis to narrow the list of culprits, above the piston top or below it.
C. the leakdown tests is only needed if the result of B is above the top of the piston or inconclusive.
The only effect of adding the oil is to seal the rings; if compression improves it is the rings, if it does not it is something higher up. The wet test is NOT for comparison between cylinders.
Flow chart:
1. perform dry compression test all cylinders
are all of the readings within 15% of each other?
YES, NO FURTHER TESTING NEEDED
NO, GO TO 2
2. perform wet compression test lowest cylinders
did the cylinders that were lowest improve to near the other cylinders dry readings?
YES. REPLACE/REPAIR RINGS.
NO, GO TO 3
3. perform leak down test
if any cylinder failed use a stethoscope to figure out if the air is escaping through a valve or the gaskets.
Yes, I understand the flowchart and purpose of each step in the compression test. I've done plenty of them in the past. Thank you kindly for sharing again. But I disagree that a leakdown test is left only for step 3 to assess just the upper end; the leakdown test has purpose for also checking the rings.
At this stage of the game, we'll agree to disagree on the interpretation of those results, because I'm simply unwilling to scrap the engine without have checked everything else I possibly could. Again, it's too much $$$ and too big of a decision to make without having every shred of factual data available to decide; due diligence demands a thorough diagnosis in such a decision. Thus, I'm going to dig deeper into the engine before I make a decision. And like I said, I don't wear my heart on my sleeve so you all can laugh at me later if I find that the engine is scrap. But I'll sleep better at night knowing I didn't make the wrong decision because I shortcut the diagnosis.
