Head Gasket- lil help

H.O.T. Diesel · 09-16-2008, 01:58 PM

So I have a 2002 chevy that belongs to a friend sitting in my yard. It seems like there is a head gasket problem. I was told he was having a heat problem, so he had someone replace the thermostats. They were installed sideways and backwards. It appears that the built up pressure from the incorrectly installed thermostats caused the coolant to build pressure and blow the head gaskets. He had coolant pouring into the overflow tank, but now that he brought the truck to me I cant even get it to start. I charged it up and bled the air out but still no luck. Im going to start by installing the thermostats correctly but im guessing ill need a link to a head gasket install procedure if anyone has one.

H.O.T. Diesel · 09-16-2008, 06:03 PM

Ok so i have somewhat of an update from this afternoon. Pulled the thermostat housing and i do not remember how the thermostats were positioned but I know i put them in the right way whenever i closed it back up and torqued everything down. One of the big 40amp fuses was blown so i arced it for now and put a real good charge on both batteries from my dodge. Bled the fuel system and pumped while someone started it and it finally came alive. It blew white smoke for about 30 seconds and then it cleared up. Barely visible white smoke at idle. I revved it to about 2800 rpm and it felt like it was defueling a bit but then again ive never had a stock truck. I let it run for about a min and it started puking into the overflow bottle, so i killed it and watched what was going on. I thought possibly whoever had screwed with the truck had overfilled it so i tried it again and it started puking after about 20 seconds. This time it was definately under pressure and it was bubbling. It wasnt hot at all, but i figured at least a gallon of fluid came out of the system so i dont think it was overfull. To my knowledge there is no water in the crankcase or diesel. I do not have access to a scanner at this moment but its on my to do list.

EDIT-- this truck hasn't been started in 3 months

jaydawg · 09-16-2008, 07:46 PM

Get a coolant tester for combustion gases. NAPA and or another parts store should have one. There is a coolant bleed screw on the t-stat housing...12mm bolt. It seems like it has a blown headgasket. The white smoke is a sign.

**daddysLBZ** · 09-16-2008, 09:10 PM

The way you describe it taking a dive after a while makes me think head gasket too.they will run with a blown one,but not good!!.A gallon of coolant=um,did someone mention the head gaskets...J/K the comp test after the bleed is the cheapest way to troubleshoot..Just use process of elimination,and when the new gaskets are put on,keep that dude away from the thermostats!!

**Tow Master** · 09-16-2008, 11:00 PM

I agree with doing the pressure test on the system. You said you checked for coolant in the oil? Weird that it blew that much though. You sure it wasnt a burp?

duramaxdr · 09-17-2008, 07:54 AM

The thermostats being installed backwards(up side down) probably caused it to over heat. Duramaxs have aluminum heads which will warp when overheated so it probably did blow head gaskets. It may also need heads replaced if they are warped.

H.O.T. Diesel · 09-19-2008, 08:43 AM

read the codes:
p0090
p0101
p0102
p0193
p0571
p0621
P0622
P0700
p1093
p1094

I realized some of these could have been older codes so I cleared them and ran it for a min but nothing but the maf codes came back up. The Maf sensor is damaged because of a less than new air filter, and maybe because of that rat that was in there. I found all of that before starting the engine but who knows how bad the filter was before he let it set for 3 months...

Anyway I looked up the codes in the code reader but that doesn't help me much as I still dont know exactly what they point to. Any help is greatly appreciated.

On a side not the oil is slightly over full, which would be unusual for an owner this careless. I thought maybe fuel in the oil which would point to an injector and make it easy, but it doesnt smell like fuel and the oil pressure is still very high. Usually diesel would lower the oil pressure. The oil is black and has the consistency of caramel... I will be pulling the injectors today to inspect the injectors and cups.

mookie980g · 12-27-2008, 11:06 AM

coolant blowing out of the overflow are signs of bad head gaskets so Ive heard. but good luck

jc1843 · 12-27-2008, 11:32 AM

He was having a problem -- that is why he changed the thermostats in the first place -- Blown headgaskets are a common problem on LB7 engines and I am sure they were already blown before he did the thermostats.

Replacing the gaskets is a lot of work, but can be done by someone with average experience. Remember that there are several different gaskets and are identified by a tab at the rear of the engine-- be sure you use the correct ones when you replace them.

Good Luck

djmercer1 · 12-27-2008, 12:14 PM

Quote:

Originally Posted by jc1843

He was having a problem -- that is why he changed the thermostats in the first place -- Blown headgaskets are a common problem on LB7 engines and I am sure they were already blown before he did the thermostats.

Replacing the gaskets is a lot of work, but can be done by someone with average experience. Remember that there are several different gaskets and are identified by a tab at the rear of the engine-- be sure you use the correct ones when you replace them.

Good Luck

was the lb7 known for head gaskets? i know the early lly had some issues...

op says the oil has the consistancy of caramel, if it has that colour, id also worry about crank bearings...