: Head Gasket Gurus, In here!

07-10-10, 05:02 PM
Hey Guys, I have just recently bought a 98 Caddy STS which seems to exhibit some of the HG symptoms but Im not too sure, and want to be 100% before I tear into the engine(let alone drop the engine!). Here is a summarized list of what the car has done:

1. Picked up car, test drive was ok, no overheat. Got 30kms from where I picked up the car and it started to overheat, shut down engine warning, into the red etc. i DID shut the engine down 25 sec after that msg appeared. left it 12 hrs, drove it home, stayed pegged normal, did not overheat or even heat past 12.

2. Replaced Water Pump, changed 2 seals, plugs etc. Car ran well, drove for 35 mins beating on it at times(within reason) and it never really heated past 1 notch after 12(which for me was fine). left car over night

3. drove last night, over 40 mins completly fine, 12 o clk all the time, over 35 kms all stop signs, no prob. Get onto the highway and drive 10 kms, get off the highway, temp climbs. Settles after several seconds after revving to 3k to normal, then the occasional 1 notch past 12 to 3/4 of the entire gauge.

4. this morning on the way to work, mainly backroads, 20kms, it heated to the same 3/4 mark max and went back to normal. Coolant reservoir bubbles after coming to stop after everytime(1-4). I drove it home, in 30 deg cel weather, its pegged at 12! This car is not consistant at all.

From here I have to kind of find an order of tackling this thing cheapest to most expensive lol. So several questions/what to check?:
-Could there be air in the system? I added coolant to the overflow/filled up rad tube/rad.
-Should I be checking the coolant crossover tube?
-Should I pull a cpl plugs to see if there is coolant on them?
No white smoke thru exhaust during idle.

I am at a loss on what to do now and what to check, i had read on HG tests and will probably do one on Mon. I might take it out tonight again. Another thing to note is no matter what the car has not gone past 3/4 of the coolant gauge AT ALL, coolant level doesnt particularly move. bubbles have me very concerned, is that normal?

Any Help Much Appreciated

07-10-10, 09:10 PM
Your symptoms don't sound good. Rent or buy a block test kit and test the air in the surge tank for exhaust gases.

07-11-10, 09:49 AM
I agree with Ranger. Not sounding good. Erratic temp spikes are a symptom of HG failure. Sort of unpredictable but when you give it wide open throttle; usually the temp will climb and climb if the HG's/bolts are done.

07-12-10, 04:02 PM
Follow Rangers advice. Thats how I confirmed my bad HG's before I had the block studded.


07-13-10, 01:49 PM
were you told motor was good? so you bought it as is? if my car overheated within 30kms i would be annoyed. unless you got it for super cheap.

07-14-10, 04:57 PM
Im having the car tested on Sat hopefully by a buddy thats a GM tech, he might get swamped, but fingers crossed he can look at it. I have driven it a couple days in a row, usually evenings tho, and today during the day it heated to the 3/4 mark after about an hour or so of stop and go, light traffic, off/on 3 times. about 3 kms from my place it past the 3/4 to the last notch but never got any higher. Im pretty sure at this point the HG is cooked. Ill keep you guys informed on how the block test goes.

Eldo - Ill see how it goes, ill prob give you a call at the start of next week
stove - bought it for relatively cheap 1600, so i figured it was ify, orig owner said it was a WP, which I did replace foolishly, however the stocker was in there so prob cheap insurance anyways

07-14-10, 09:22 PM
bought it for relatively cheap 1600, so i figured it was ify, orig owner said it was a WP, which I did replace foolishly, however the stocker was in there so prob cheap insurance anyways
That's what they always say. Dead give away. Cheap price because of a water pump? Give me a break. No one sells a car because it needs a water pump. He new what he had and was looking for someone to unload it on.

07-14-10, 10:10 PM
You wouldn't believe the amount of people who try to sell a Cadillac that way in Ontario. I called a while ago about a '98 Deville for $1200. The starter was shot apparently so the vehicle could not be started. Right aways he mentioned a new water pump and new radiator. My opinion?

-head gasket blew; explaining the cooling system tune-up
-head gasket leak got worse; hydrolocked a cylinder; took the starter nose-cone out.

People don't change radiators and water pumps until either a leak occurs; or overheating begins. Sometimes as preventative maintenance; but not very often.