My wife’s car lost compression on cyl 6, same results wet or dry turned out to be broken exhaust valve spring.

 

I took the EGR off last month when I replaced it and did not blow air through, i did clean out the main
orifices in the intake manifold. Once I get it home I will add this to my list, I hope to have it home by this
weekend and start tear into it. Need to clean some shelf space first so I can label and organize all the parts
as I take them off, hope to prevent having left over parts ;-)

 

You do realize we are all patiently awaiting your analysis right?

 

I am not accusing the guy of being dishonest, I will get the exact compression readings when i pick the car up. I mean
if I run a compression test and they are fine that's a different story. I will also try the wet compression test, per the Hagetry
video ZWILDZR1 provided, which will help me determine if it's the rings or at least rule that out. I have a compression gauge,
air compressor and a perfect opportunity now to buy more tools
If I take the heads off I will then decide on whether I will add a mild cam and lifters + valves while it's apart.

 

I think that's called mission creep, that's how I went from just replacing the water pump two years ago into timing chain, oil pump,
fuel pump, oil pan removal with a visual inspection of the main bearings etc....oh yeah I also had the shop put on the new pads & rotors I
had on a shelf waiting to be installed.

 

Sounds like you got this.. time is your only opponent. A leakdown is the ultimate test.. you can typically hear where its leaking. a stethoscope is helpful but not necessary..I hope the plug holes are easier to get to than the lt1.. Let us know.

 

I will definitely post the findings as soon as I get the heads off 👍 Trusty Good Sams Club towing brought my car home, well worth the $100 or so I pay a year, and the shop is sending their readings in the morning. Seeing how this is the last weekend of deer season in Georgia I will probably be in the woods with my fried/mechanic. Details to follow soon.
Thanks everyone

 

nothing wrong with your head gaskets or rings. They just don't go bad sitting in the garage. you really need to focus somewhere else. Fuel system would be a great place to start then the ignition system. Good luck and stay away from the shop that asked you 3500 to put head gaskets on it.

 

It's been a long time then for you. Book time for this job is 14 hours assuming that you have everything that is considered interfering.

I'd imagine a good part of that time is removing & replacing the hood to make it easier to remove the engine. Some folks on here

say you can pull the motor without removing the hood, so you can cut that time down.

 

Did you do ANYTHING different, just before you parked the car, when it was still running well? Maybe something simple, and forgettable, like filling up the gas tank? Did you get a bad load of gas? Or, also keeping it simple, is the car's battery going bad?

 

Read his original post:
"I have a hard time believing that because the car ran great until one morning I went to start it and it would barely run."

 

leadfoot To the best of my knowledge I had not done anything different, ran one day and not the next. I should know something within a week, will begin by draining
radiator, performing compression test (wet and dry) and leak \down test. I am also expecting an email this morning from the garage that had my car with the comperssion
readings thew saw plus which valve(s) were loose. Somebody else mentioned possibly blocked EGR passages in the intake manifold, i had been experiencing off and on
for a while an intermittent EGR valve check engine light that always went off the next time I started it. The EGR warning light only came on after driving the car
for more than 30 minutes (+ or -). I anticipate at least taking the heads off, replacing the head gaskets, have the heads inspected by a local shop to determine if there is any
warpage from heat over the years, it has never overheated (boiled over) since I've owned it. While it's apart I will thoroughly clean the intake manifod and then it should run like
new (fingers crossed).

 

Is it really necessary to take the hood off to remove the heads? I am not pulling the block, just
the heads and there seems to be plenty of room for that with the hood up. Thoughts?

 

I did read his OP. Let me say this, based on personal experience.....a number of years ago, the evening before I went on a vacation, I drove a SHORT distance to the "corner convenience store", where I filled the car with gas. I didn't know that I had gotten a bad load of gas. However, there was enough gas in the line, between the tank and the engine, so the car actually ran well for 4-5 miles afterward, enough that the car didn't start "skipping" until I was on the road. In my case, I had to endure this, until I A) had burned off some of the gas so I could refill the tank with a decent amount of "good" gas; and B) I was able to purchase a bottle of fuel treatment, to try and "neutralize" the bad gas.

Things do, sometimes, just crop up quickly....

 

I thought of another explanation.. if it is a cyl to coolant leak it would have run ok but when sitting coolant would have leaked into the cyl.

 

That's always a possibility, I'm sure, but I would think that something as major as that, wouldn't occur "all of a sudden". Generally speaking, those types of problems tend to start as "running a little rough", then progress to "running really bad". They usually don't start, literally, overnight, and that's why I was suggesting that the OP look at the simple and easy to fix possibilities first, before sinking a lot of money chasing "possibilities" that aren't the real issue.

And to the OP, I really like those wheels! I had a similar set on a mid-90s Z/28 Camaro that I used to own.

 

We started working on my car today, first put my car on the new wheel dolleys I bought using my new
floor jack (Harbor freight is dangerous....). The shop that worked on my car provided readings for
three cylinders (2,6,7) all in the 65-70 range. We did compression tests on four cylinders so far,
(2,4,1,3) and all of our readings were between 150 - 175. We are going to try with a new gauge
tomorrow just to verify our numbers, the gauge we used today is old. So either our gauge is off or
I can't trust the numbers provided by the shop. I almost hope our readings tomorrow change or
the shop straight lied about the readings. I am intentionally not stating which shop it is, I won't
put their name out until I know for sure. The question still remains, when we retest tomorrow if
my cylinders are all 150 - 175 do I even have a head gasket issue? I'd hate to pull the heads
for no reason.

 

Of course, most following this were pessimistic about the shop based on your description. However, lying is a bit severe, Id like to think that they had some kid do the test and he did it wrong. If he didn't seat the connector all the way into the plug hole he would have possibly seen low readings. I doubt your old gauge is wrong because I believe those are correct readings for the l98 are they not?

However, bad diagnostic or a lie, the shop would have cost someone a small fortune and needs to clean up its act. You might call or stop in and ask for the owner and see how he responds.. if he is very apologetic and you get the idea he is going to take action to not let it happen again Id drop it.. if not, Id post a bad recommendation on yelp or other social media forums.

HOWEVER, I did this once when an hvac guy overcharged me for freon because it was for a tenant and a very hot week. I posted a bad review and he came back two times and cut my freon line. One on the old system and then on a new one when I had it replaced. They probably have your address so food for thought You never know what people are capable of.T

EDIT: What's funny is the hvac guy did me a huge favor because my home insurance fully covered a $4400 heat pump install.. so I got the last laugh.

 

FYI, from what Ive read 150 might just be a little low.. but not bad enough to cause a problem like yours. Also are you holding the throttle wide open when you do these tests?
It is relatively important that they all be within 10% of each other.. however, once again, some variance from that wouldnt make your car run like you have indicated in my opinion.

You really should do a coolant pressure test to finish up this diagnostic. It will show even a tiny head gasket leak.

Also, Im not sure of you should be testing this hot to determine actual pressures.. someone else should chime in.. and if you want to go a step further squirt a little oil in each cyl and retest to give you some idea about your ring seals.

Id be prepared to run diagnostics on your ignition and fueling system... fuel pressure gauge would be a start. I hope you bought more stuff at HF.

 

150-175 is fine. i forget the % of difference that is allowable, but i do know if you hit between 150-175 on all 8 cylinders, that is not the problem, maybe turn to spark voltage or fuel pressure from there. i actually had problems with my truck last summer. it was showing spark by using the old screw driver in the end of the plug trick, problem was. it just didnt have enough spark. you need around 45k or more. you can buy a cheap spark tester that has a gauge to set for like gm / ford so on at autozone for around 10 bucks. might be worht looking into. a 50 dollar coil would be a nice easy fix
also "if" you do that check spark coming from coild wire first, then check the cylinders, it may be possible you have a bad cap or rotor.