Possible blown head gasket?

[rhauf]

A few months ago my '93 started running a little rough right when i restarted it, if i had shut it off while it was warm (like i went into a store for instance, when i'd come out it would run rough for 30 seconds or so then smooth out)

anyway that problem has been getting worse, so i figured it was just time for a tune up. however over the past few weeks ive been topping up the coolant more and more often.. and the running rough (sounds like missing) has become almost constant - always when its idling. and now i'm filling up the radiator and after 50 or 60 miles of driving, i'm able to get another gallon in the radiator. There don't appear to be any leaks (i started it and let it run for a while in the driveway.. didn't leak a drop) so the only thing i can figure is that it's getting into the engine and going out the exhaust.

the oil does not look contaminated.

current mileage is 230,000. I replaced the heads when i bought it at 160,000 miles (both heads were cracked, lady who owned it had run it out of coolant) it has never been overheated since.

so i'm thinking it must be a blown head gasket. the thing is, that it doesn't get hot real fast, or have contaminated oil, or any of those likely symptoms... do these engines often get coolant leaks in the lower intake plenum? or should i go straight to head gaskets?

or is there some obvious simple problem i'm not thinking of?

 

[rickybobby]

what color is the exhaust

 

[rhauf]

what color is the exhaust

Exhaust is invisible, although when i started it in this morning, i thought there may have been a bit of (white) steam from the exhaust, but it could have just been my imagination. (exhaust always looks steamy in the morning, right?)

 

[rickybobby]

if you were losing that much coolant through the exhaust, it would be white all the time, and smell like coolant. I would try to get my hands on a pressure tester, and test it not running.

 

[rhauf]

I was detecting some coolant smell a little now and then.. that could have been any leak though.

i just cant figure where else it could be going. also it's running terrible now. I think ill pull the intake and look for a leaky intake gasket. then the heads. its time for a new set of hoses and stuff on it anyhow. might as well pull everything off to get to it right?

 

[rickybobby]

thats an awful lot of work for a guess though

 

[rhauf]

Well, problem found.

after exploring other possibilities (the water pump/timing cover seal was leaking slightly) i finally decided to pull the engine.. sure enough, drivers side head gasket was blown between the rear most cylinder and the water jacket.

took the heads to the machine shop and they were warped about 7 thousandths, but no cracks. had them resurfaced.

 

[mrgunny]

Mines been doing the rough idle thing also, but only for a few moments and only if it hasn't been sitting too long. Doesn't seem to do it if I've removed the gas cap - like going to the gas station.

Q- Did the replacement of the head gasket solve your rough idleing problem?

I recently had some foot surgery, so I left my truck in the garage and disconnected the battery cable. Week or so passed, and then I noticed a puddle of coolant underneath the truck. Checked all the suspects - seems to be coming from the front - somewhere in the area of the waterpump gasket/manifold. Wiped everything down, started up the truck - nothing coming out. Waited a day, still no leaks anywhere. Gonna do some more checking just to be safe.

Ed sends

 

[mrgunny]

Okay, to followup. I have about a half of bead of coolant sitting on one of the lower parts of the oils pan cover.

 

[rhauf]

I had two rough idle issues. one was a sort of surging idle caused by a crack in the intake pipe between the MAF and throttle body (right next to the throttle body) the other was caused by the coolant gushing into the cylinder (once it got bad enough) and that would cause it to misfire. changing the head gasket solved that. fixing the leak in the intake hose fixed the other issue.

if your water is external to the engine, its probably not a head gasket issue. more like water pump or a pinhole in a hose.