need your help (engine cranking)

[Ground hawg]

Ok, i've now blown my second engine this one with just under 8k on it. with only 39k on a 99 wagon i'm doin pretty good. so what i need to know is this. is there any way to crank the engine over from inside the engine compartment while i run a compression test on all the cylinders.

Thanks in advance Ground hwg

[BlueHUMMERH2]

This is really out of my league, but if you remove the connections to the crankshaft, couldn't you turn that manually to adjust the position of the pistons? Is that what you're trying to do?

[Ground hawg]

sorry, to get an accurate reading I need to turn the engine 8-10 revolutions per cylinder. thank anyway

Grnd hwg

[ssgharkness020147]

No you need to crank on it to get a max, reading. Out of curiosity why do you want to do a compression test? Do you think you blew out a piston, or washed the bore? If you are concerned about a cracked block, head, blown gasket a compression test will not accuratly diagnose any of those.

[Ground hawg]

The reason for the compression test is so that I can find which cylinder is leaking, with out having to dissasemble the whole engine. the only sighn of a problem is that the engine presurises the cooling system to such an extent that it blowes all the coolent out the system. this as you say could be caused by several different things. this is only a tool to speed up the prognossis.

[ssgharkness020147]

A compression test is not really going to help there either. I went through this same thing a while back. I talked to Diesel Depot down in GA, and here is what they told me to do:

Pull out the dog house and engine cover with the truck on flat level ground. Then to remove the two coolant block off plates in the rear of the block. You know the ones to install the rear head cooling kit? Those plates are the ones I'm talking about. From there you start the truck, which ever side has a blown gasket etc... will have coolant bubbling out of or in that port. I'd try this, if your truck wont fail a coolant pressure test its not gonna fail a compression test either.

On a side not why not just pull both heads? In the long run you'll thank yourself not having to worry about blowing another crappy stock headgasket. And you can have both heads pulled checked for level, and magnufluxed while you are at it. Further preventing future problems. Just my 0.2

[Ground hawg]

Thanks for the advice. looks like thats what i'll be doing tomorow

[ssgharkness020147]

How has your heat been working Groundhawg? When I blew out my headgasket the heat was piss poor. No matter what you did it would not produce max heat. When you were moving it would put out ok heat, but not the temps that it should have been. Then when I would get off an on ramp and begin to slow down the heat would instantly drop down quite noticably to luke warm at best. Also has your engine temps been? Have you noticed the gauge fluctuating alot? These would all tell tale signs of an internal problem. ie bad headgasket, cracked head, cracked block. As you said earlier the surge tank was over flowing, which again is not a good sign. I hate to say it but I think you'll have to pull the heads off. I do have another VERY easy way for you to tell if the engine is fubar. Good autoparts stores will sell is called a cumbustion gas leak detector. It is a liquid that you poor in your coolant. I believe you then fire the truck up to let it run a couple of minutes. If you have traces of combustion gasses in your coolant the leak detector will turn it a different color, blue or something like that I think. I would give this whirl, it will tell you for sure whether or not you need to tear the engine down.

If you choose to buy it make sure that you dont buy leak dector. Leak detector will dye the coolant which you will only be able to find external leaks. Do not buy this, it wont help you. If you want some though I do happen to have a case sitting around, and I'll happily send you a vile of it.

[Ground hawg]

acctualy what ever is causing the leak blowes the coolant out the system so fast I couldn't tell if there was heat coming out of the vents or not. i'm lucky it didn't either blow the rad or heater core(i just replaced that about a month ago). i'll let you know what I find. this engine's only got 8K on it, so the company i bought it from are going to pay for all the replacement parts. i've just got to put in all the labore.

grnd hwg

[Ground hawg]

Carey. did first check today on engine
1) no oil in coolant
2) no coolant in oil
3) conected clear hoses to block mod. bubbles seen fron passenger side.

hope to start removing engine tomorow. I'll keep you up to date on how i get on.

Thanks again grnd hwg

[ssgharkness020147]

Bummer. The no. 8 cylinder is on the passangers side of the block. Hope its not a cracked block. Best of luck and keep me updated.



Carey. did first check today on engine
1) no oil in coolant
2) no coolant in oil
3) conected clear hoses to block mod. bubbles seen fron passenger side.

hope to start removing engine tomorow. I'll keep you up to date on how i get on.

Thanks again grnd hwg

[Ground hawg]

Carey, got the engine out and striped off the head. nice crack in #8 about 1 1/2 inches long left lower quater about 1/2 inch below barrel top.

looks like i need yet another new engine.

wife's getting realy pi$$ed of with my H1 now. talking about selling it or else. you know any body that might be interested in 44 year old Thai lady
ridden hard but still in good shape???????????????????????(and good lookin).

[Ground hawg]

Hi Carey, picked up the replacement WARRENTY engine thursday night. unpacked it Saterday morning for the install and found that the casting that the injection pump mounts too is all smashed up( about 5 pieces ).
So shipping this one back on Monday, I'll let you know how long it takes them to send me another one. I was hoping to have this all finished by Christmas. looks like it may spend yet another one in pieces.:crying: :violin:

[ssgharkness020147]

Damn. Talk about some bad luck. Glad to hear you've got it figured out though. Hopefully things will perk up for you soon, after going through this again your due to have the HUMMER gods smiling upon you. Before you install the new engine get the casting code off of it to see when it was manufactured. Ideally you will have a block made after 03, if you do another #8 crack should never happen again.

[Ground hawg]

Hi Carey, got the replacement Engine. Everythings lookin good so far. Started fitting it in yesterday. so well have everything up and running in a few days. (just hope this one lasts better than the other one).

Well hope everybody has a great Christmas and new year.

Regards Ground hawg:D