Compression issues

[jughead]

I will keep this short, b/c my temper is off the hook.


So I had the IIRC 1x cam package installed. Twice now after install, it has cut after 20 mins.

First we thought the pushrods were too long(even tho IIRC said stock legnth works.) So I got pushrod checker, and tried shorter ones, no goose. Then I got used L26 heads. Nope. Then they dropped the motor, and replaced the pistron rings. FIntally, it ran again, but damn, only 20 mins again. Then MAGICALLY sugar was in the tank. I know the Sugar thing is BS cuz it doesnt desolve, and I dont think the injectors, let alone the filter, let it go thru. I was getting 145psi(I think) in all cylinders. Now only 50 again. SHop claims the honed the block, but I am not sure. I pulled the dipstick, looks like graphite in there, not sure.

SO I need some ideas. I dont think its a PCM issue, or valvetrain issue. I told them I WILL NOT pay another dime, it came there in GOOD condition, and thats how it should be done. I think the sugar thing is a spoof from them, and I am not buying it one bit.

So I had L26 and L36 heads, all the stuff from the 1x package, etc. Seems like pistons are seized, so I am sure the rings are shot, YET AGAIN! They already replaced them before, and samething happened first time.

Please, need any and all suggestions. Its being broke down tomarrow.

[techsan23]

Re: Compression issues

So you found metal shavings on the dipstick, and the shop thinks there is sugar in the fuel tank? Sounds more likely that you lost a bearing. Did you notice your oil pressure doing anything in that 20 mins?

[jughead]

Re: Compression issues

Sugar in tank is spoof I think, cuz they dont know whats going on. Twice now it started, now still same compression issue. I was thinking they either didnt lube everything right, and didnt pressure the oil through thr turbo. Theres ALOT of sugar in tank, but thats BS, I googled it. Mayb a bearing, but that wouldnt affect the compression would it?

[ssms5411]

Re: Compression issues

I wouldn't let the shop touch it again, maybe their messing with it to get more money. They may have messed the timing up when installing the cam.

[jughead]

Re: Compression issues

They know there not getting anymore money, and they agreeed. A family friend is there working with them. This shop HAS done good with me on prior installs(like my GN I had years before) Maybe they just dont know. but given what I have said, what would cause this compression loss? All gaskets have been replaced twice. I was thinking the UIM and LIM cuz there ported, or maybe the 60lb injecors?(PCM is bench tune from IIRC) Just need some good ideas so I can have my people do it. NOTHING ELSE IS BEING SPENT BUT ON THEM, that is what they agreed on. Anything damaged or vandalized by them is THERE responsibility cuz the cars been there about a month

[techsan23]

Re: Compression issues

Its weird that you would loose compression on all cylinders. Makes me wonder if the valves are staying open, but you were holding 145 psi from the beginning. It may be worth pulling the valve covers and rolling the crank over with a wrench to check the valve events compared to the pistons. If there is in fact metal shavings the whole things going to have to be blown apart unfortunately.

[LETZRIDE]

Re: Compression issues

Is the car making any sounds while running? If the rods were infact too long, you may have bent all your valves...but you woulda seen that if you swapped heads?

UIM/LIM/injectors should have nothing to do with compression.

If you lost a bearing it should be knocking I would think.

[jughead]

Re: Compression issues

What I am thinking is that they didnt put the oil in right, didnt set the timing right, and got rings got hot. When they replacede rings, I dont knwo if he honed the block or even if he did, good enough. I will put have him take off the rockers and start it to relax the vlaves when THEY, the shop(remember I told them liability is on them, I love studying the law). The heads are now L26 heads. Or its either they did one that wrong the first time and now something different the second time, or they didnt install the springs, retainers, valve locks and lifters correctly.

[jughead]

Re: Compression issues

Anything guys? Care was fine befor install, so this is mechanical. What can or will casue loss of compression after initial start up?

[ssms5411]

Re: Compression issues

Timing off, did they degree the cam correctly?

[LETZRIDE]

Re: Compression issues

my guess is your valves are still being held open...I remember you said you have the OE-R lifters...there is next to no extra play with those...you have to make sure they 100% set the valve lash right with regards to how the OE-R lifters specify...if they set the valvelash the same as for a stock lifter your valves are going to most likely be held wide open.

I think there is like a 0.005 leeway with the OE-R lifters...stock lifters give you an extra 0.060 cushion I believe...thats a BIG difference...but don't quote me on those numbers.

directly from ZZP's tech article:

To check for lifter preload or lifter squish you need to first get to zero lash. Turn the engine over so that one valve on a cylinder is open. Because one is open, you know the other is closed, meaning the lifter is sitting on the base circle. With that lifter on the base circle loosen the rocker bolt and then retighten with one hand while spinning the pushrod with the other. This way you can tell when everything first makes contact (the valve is touching the rocker tip, the pushrod is touching the rocker & and lifter and the lifter is touching the cam). At this point of first contact you are at zero lash. Everything past this point is lifter preload. Continue to tighten the rocker bolt until the bolt hits its snug point. This is how much lifter preload you have. Each 1/2 turn of the rocker bolt is ~.050 of lifter preload. Your goal is to have between 1/2 turn and 1.5 turns if you have stock lifters or 3/8 turn to 1/2 turn if you have Comp lifters. As you can see the stockers have a lot more room for error.

If you have too much preload and you have exhausted the adjustment of the lifter, the valves will stay open and the car will not start due to lack of compression. If you have too little preload, the valve train will be noisy and you risk exploding a lifter and having a very costly repair.

Full article can be found here http://www.zzperformance.com/grand_p...les1.php?id=50


I'm still putting my money on this is your issue...it's the only way I can see loss of compression across all your cylinders. IMO it is a fairly easy mistake for a shop to make that isn't familiar with the performance parts for these specific motors...especially if they didnt read the box, which most people don't. Because let's face it here...virtually every aftermarket part you install on our cars gets torqued to factory specs with the exception being to ARP head studs and the OE-R lifters...that's about all I can think of...


Steve, If the timing was off wouldn't you have some compression in some cylinders? I would think that timing would throw off only certain cylinders at certain points as far as compression?

[jughead]

Re: Compression issues

Issue solved. I bought a P&P UIM and LIM. Didnt inspect the parts when I had them go to be installed. Metal shavings everywhere. I have now finished the P&P, matched gaskets, getting new rings, honing engine out and putting it all together. I am now in the FT Hood area(not the great place they claim) and will be using my next 4 day pass to go back to Omaha to get car.

[ssms5411]

Re: Compression issues

Glad they found the problem.