[TJM]

Hi All

Have a 1987 Z2.4L D series truck. I have replaced the head gasket twice. The last time I pulled the head I replaced it with a remanufactured head cause we found small cracks between the valves on 2 cylinders. Anyhow the head gasket has just blown again..%$#@. The motor did not overheat and there is no apparent problem with the deck of the block. The gasket lasted about 6000klm. Is this a common occurrance for Z2.4? what can be done to help prevent this? is ther a copper gasket available? hate to park my little utility truck for good...
Thanks TJM

 

[smikster]

you got that dead on...big prob with them... other then that a great motor. I don't have one that old yet so can't help you but when you fix it be sure to run cleaner threw it all

 

[jkretzer]

i was told by a machine shop that i bought a reman head from for mine that to insure that the HG didnt blow right away and to make it last, take a 1/8 drill bit and twist it with your hand in the tiny vent holes inbetween the cylinders on the block. it goes downward at an angle from drivers side to pass. they get clogged very easily and that wont let the crankcase vent and causes pressure to build. hope that helps. o and dont use a power drill, you will most likely go right through the block.

 

[TJM]

OK well thanks for that info dudes, I have checked into this some more and just about everyone i ask says oh yeah one of those, they are bad for that.
I talked to the guy who owned the truck before me and he even did it once.
that makes 4 head gaskets gone in total...that i know about. I have never heard of the vent holes you speak of, are the holes actually there to vent cylinder pressure constantly? i mean each time the one of the valves would open would this not vent out any pressure?

 

[zanegrey]

did you check to see if the block was sqaure ??

did you check the timing cover to see if it has been scored by the tc and is allowing colling fluid into the engine oil ?

did you use new head bolts..?

are you using the correct spark plugs..

do you have any vacumn leaks.?

do you have the correct thermostat ??is it new or old?

why are you running it so hot that it blows??

does the temperture gauge work ??

have you read the codes ??

 

[TJM]

answers to inquiry

Well i did not do the entire job myself as it was my mechanic the last time. I can't answer the questions about the block,timing cover. I would need to ask if these were checked. They did not use new head bolts, the spark plugs are new but can't tell you the number right now, there are no vacum leaks, the thermostat is/was new at 180 deg F, it has never ran hot according to the temp gage which I assume is correct and I have not read the codes. Which of these would be the most likely cause? My thoughts are that if the deck of the block is un square or that if there is an over heating issue,one these would be the likely culprit. Also is there a cooling line that feeds coolant through a hard line roughted behind the head close to the fire wall? Last time my mechanic told me they cleaned it out. He suspected that this may have caused the last blow out. How about the water pump? this motor has over 500000Klm Thanks for your insight good questions/food for thought

support all coallition troops over sea's!...TJM

 

[zanegrey]

the block not being square is a major culprit.

new head bolts not being used is very high on the list as well.

the hardline behind the head is the egr tube.

since the engine did not overheat and the head gasket went , i am guesiing block problems .

either out of tolerance or blocked coolant holes..

everytime that head comes off and goes back on you must put on new head bolts..they stretch when torqued so using them again is an unknown...as it were..

 

[johnboy26]

the biggie is getting the bolts torqued down the only time ive ever changed a head gasket was my own fault due to me not checking the head bolt when i bought the rebuilt engine

 

[scout]

might want to check the areas around the head bolt holes. I found small spider cracks around some of the bolt holes by #3 and #4 cylinders. Very difficult to see.