head gasket help

[dohcfiend]

recently i was driving my car when the coolant light came on the temp guage went up to about 240 and fluctuated from 240-250-210 all the way home. heater didn't work. got home popped the hood and the overflow tank was almost full hardly any coolant in the engine.

also i recently flushed the rad and now there is some scaly black residue in the overflow. i think the stat is to blame, but i am not a tech.

[SappySE107]

I think the temp of the stat wont have anything to do with your problem.

[dohcfiend]

what i was referring to is the stat sticking in the closed position.

[SappySE107]

how old is the coolant?

[dohcfiend]

unfortunately i am fearing the worst. when i hit the brakes slowing down from cruising speed, i feel a miss in one of the cylinders. and i am noticing some larger than normal amounts of white smoke coming from the exhaust, and i had the car in park, tapped the gas, and i hear a little what sounds like spark knock(maybe a little valve tapping). the scanner say the knock strength is 1 and there is no retard. every so often the weak cylinder will say 1. i checked the plugs, all of them looked sooty(cause i am running colder plugs) except one of them(the left plug on the rear bank) which looks clean.

i am guessing a head gasket or maybe an intermittently failing coilpack?

i am hoping for the coilpack but i have a bad feeling.

[dohcfiend]

Title mess up

how old is the coolant

i replaced it about 2 weeks ago when i flushed the rad. also i messed up with the title that is what threw you off. i should have put a comma in it or worded it differently. either low coolant, stat to blame. or running hot stat to blame. sorry about that. i have a stock stat BTW.

[dohcfiend]

and i had the car in park, tapped the gas, and i hear a little what sounds like spark knock(maybe a little valve tapping).

i was wrong about that i tried it from the engine bay instead of inside of the car. the sound described above is heard in my hollowed out cat. but i am going to pull all of my plugs wires one at a time to check coilpack spark on all 6. be back in a few.

[dohcfiend]

well...on idle spark is present on all 6. next i will wait for the engine to cool and remove the stat. also maybe the increased smoke is from the new resonator(glasspack). right now this car is confusing the shit out of me. o well 1 step at a time and hopefully i will find the culprit.

[dohcfiend]

the stat housing, it is connected to the lower rad hose and next to the water pump? if so the car has no stat.hmm.

water pump? i don't think so because all the fluid moves to the overflow.
timing? maybe the belt is stretched.
headgasket? possibly, i am thinking that black residue in the overflow could be the missing soot from that clean plug.
coolant blockage?
i am stumpted.

[SappySE107]

Did you just say all the fluid is moving to the overflow? You have a blown headgasket for sure. Mine did this when I didnt tighten the bolts down enough. The compression in the cylinder would pump up the cooling system, pushing the coolant out the overflow. This will make the gauge jump around as well.

The stat is in the lower intake, under the throttlebody area basically. Upper radiator hose goes to it.

[dohcfiend]

i checked the plugs, all of them looked sooty(cause i am running colder plugs) except one of them(the left plug on the rear bank) which looks clean.

yea i am inclined to agree. i filled it with coolant and took it up the road for 3 miles, came back and that badboy is bellowing white smoke now. DAMN IT!!!. knowing my luck it will be on the hard to get to side. and if that isn't bad enough i still haven't learned how to time these engines yet.

judging from what i told you about that 1 plug being clean, do you think that is the head gasket that is bad? well on a positive spin there is no oil/coolant contamination. thanx for your help.

[Juglenaut]

water pump? i don't think so because all the fluid moves to the overflow.

Just because the overflow is filling up does not mean the pump is pumping it to the overflow tank.

The cap on the radiator is a 12 psi (or about 12) cap anymore it will flowover to tank, however it is very possible for the head gasket to leak air in on compression/power stroke, but it is just as likely to suck in coolant.
The ETS does not gauge temperature based on pressure and the ECM uses this sensor to send to the temp gauge. This is a liquid temp sensor, and does not usually respond to air temp that fast.

It would have to be a major leak for the heat of the power stroke to heat up the coolant. Even then the coolant should degrade really fast and idle will be crappy.

Water pump might have failed.

By the way it sounds what oil may be in the coolant has leaked out the overflow.

I don't think the spark plug would be clean on the cylinder with a leaky gasket.

If your other plugs are carbon fouled it would indicate to cold of plugs or under-gapped.

If coolant is burning in the cylinder usually the plug has a film on it that resembles the color of the coolant or a very white filmy soot, a color of green is not normal. You might even get slight water deposits on the plug. Coolant is a gylcol based compound I believe and does sort of have a oily feel to it and is harder to burn than oil and will have a very noticable sweetish smell when it is burned with gas.

Tear the top engine down to the heads and inspect them, you should notice if there is a bad head gasket leak.

[dohcfiend]

yea i was wrong about the contamination. i saw a little milkshake in the cam banks.

the cylinder with the clean plug i was talking about i looked at all the cylinders through the intake ports and that one had a white residue on it in the little walls above the intake valves.

the idle was a little shitty like a miss or something.

the plugs are 2 steps colder, but have stock gaps.

for my info though. the symptoms i described there is no chance of a cracked block,cracked or warped heads or anything is it?

i hope not.

also if only 1 gasket is bad should i just replace 1 and ride or replace both?

[pocket-rocket]

Engine work is like brakes, replace things in pairs. And our Cutty parts car had a t-stat in that "Y" junction where the lower rad. hose, the hose that wraps around the front of the front head bolts too. Never taken the one off of my two cars, so I don't know if that is stock, or someone thought one went there since I haven't seen anything about it in any of my books either.

[Juglenaut]

Cracked haeds are possible...I won't deny that, but most of the time warpping happens if the engine is overheated serverly and then cooled faster than normal.

The expansion and contraction is what causes the warpping or cracking, the effect worsens if the engine cools to fast or the engine is overheated in a cold climate.