2F head issues (2 Viewers)

[4rnr]

My buddy has a 84 fj60. And he has had lots of problems with overheating. (probably bc he drove it with a closed thermostat for 6 mo. vapor locking it every day) Anywho There is no evidence of a blown head gasket except he took it to a shop and he said there was a high level hydocarbons in the coolant indicating exhaust in the coolant. I think it might be a bad HG and/or a warped head. what do you think.

Also what does it cost to have the head remachined. Also if the head is remachined do I have to get the block remachined.

 

[tfdcruiser]

90% of the time you have hydrocarbons in the coolant it is a headgasket issue it would be 100% if he also had water in the oil. Long inline motors are very sensitive to losing head gasket seal if they are overheated especially repeatedly. If you have access to a leakdown tester it would help diagnosis but it does sound like at the least a head gasket leak possibly a warped head or both. I would replace the head gasket, and machine the head surface to clean it up and then check the block surface with a machined flat bar. Block warpage is relatively rare but it sounds like he repeatedly overheated his motor so it is quite possible, in which case only a tear down would allow the block to be milled.

 

[76FJ40]

I paid $80 to have my head milled 0.08" when I burned a valve. It cost extra to have that much meat removed but I wanted to raise the compression.

 

[wesintl]

90% of the time you have hydrocarbons in the coolant it is a headgasket issue it would be 100% if he also had water in the oil. Long inline motors are very sensitive to losing head gasket seal if they are overheated especially repeatedly. If you have access to a leakdown tester it would help diagnosis but it does sound like at the least a head gasket leak possibly a warped head or both. I would replace the head gasket, and machine the head surface to clean it up and then check the block surface with a machined flat bar. Block warpage is relatively rare but it sounds like he repeatedly overheated his motor so it is quite possible, in which case only a tear down would allow the block to be milled.

I've overheated a few 2f's and the head gasket was always good....

late 2f are kinda notorious for cracking heads when really hot. I've always replaced the head and things turned out fine.

 

[4rnr]

what would it cost to have the head rebuilt. This truck has 200k and Im going to tell him to have the carb rebuilt to.
Its amazing this thing still runs. He blew the t-stat and had a bad engine temp sending unit. (nice combo) so I suspect he was over heating it every day.

 

[Gumby]

If it's gonna be down while the machine shop cleans, magnafluxes and pressure tests the head and mills it, send the carb out to Jim Chenowith. not only will he fix it, he can tell you how to make that desmogged motor work right. make even more sense to have the machine shop cut the valves and install new valve seals. If you decide it's too much to have the valves cut, at least bring the head out to the shop and we'll lap 'em and install new seals.

 

[Doug_S]

It cost extra to have that much meat removed but I wanted to raise the compression.

Why machine more off the head. It'd seem to me that it'd cause predetonation more easily

What would it cost to have the head rebuilt. This truck has 200k and Im going to tell him to have the carb rebuilt to.

When I checked with a local shop, I was quoted a price of $90.00 for the machine work minus parts.

 

[wesintl]

milling the head give a little more compression and power.

I'd pull the head and take it to a machine shop first to see if it's good. Have them magnaflux to make sure there are no cracks and go from there. From there shave the head a tad, get a valve job and have the oil weep fixed so it never pops and you lose all the oil.