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HybridZ

L28ET almost overheating all the time


Omar

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so i have a 240Z with an l28et. the motor is pretty much stock just intake and exhaust. it used to go 3/4 of the way to hot on the temp sensor when i was pushing on it alot. one time it got to the H when i was really beating on it on the highway.

 

since then every time i drove it it get about 5/6 of the way to H but never more. And it bubbles into the overflow after i turn the car off. and now it happens with just normal driving after about 8 minutes. but it will idle forever and not get past half.

 

i did a leak down test at about 60psi and detecting nothing as far as a bad HG or warped head. there is no burning of coolant and nothing leaking. I also took out the thermostat, just to get rid of that variable. and it didn't help.

 

any suggestions.........please?

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Only timing you need to worry about if you don't mess with anything is cam timing.

 

Just scratch a place between two circles on the gear, then mark the two links that go to the left and right of that scratch.

 

I've done it this way twice. Makes for a headgasket job in less then 2.5hrs.

Mario

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Go by the piston position. If number 1 is up and the intake and exhaust valves are closed then you're at TDC. I got lucky because my crank mark is still accurate (of course I checked to make sure).I just spin the motor until the cam number 1 and 2 lobes are up the timing mark lines up at 0 on the plate. The only time I had a problem was when I replaced the oil pump and didn't prime it before cranking. No oil pressure puts no pressure on the chain tensioner which allowed the chain to skip. Of course I didn't realize this until I found the eye brows in the pistons from the exhust valves.

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...So did I miss something? How come you are jumping straight to 'replace the head gasket' for this problem? That's a pretty major chunk of work if you haven't isolated the problem yet.

If you are going to 'shotgun', start with the easy stuff first.

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The only time I had a problem was when I replaced the oil pump and didn't prime it before cranking. No oil pressure puts no pressure on the chain tensioner which allowed the chain to skip.

 

well if i open the radiator cap and i quickly tap the gas, bubbles come out of the radiator, thats a bhg as far as i know.

 

how do u prime it first??

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