Surprise Overheat

[TagHeuer]

So I just got through dealing with my DII not starting when another issue arose today and I'm not seeing an obvious thread out there. . .

Took a quick local drive (back roads at low speeds) in the snow when i noticed that the heat completely cut out. Almost immediately after that the temp gauge began to climb and topped out as I pulled into a lot. An investigation under the hood revealed what looked like a 'high' level of coolant in the expansion tank. In addition, there was a large amount of coolant all over the fuse panel cover as if it was blown out of the tank. No obvious cracks in the tank. . .coolant expelled from the cap perhaps?

I'd like to start diagnosing this on my own but I'm not sure, at this point, where to start or if its best to take to a shop for help.

As always, thanks in advance!

 

[roverover]

What is the test level of your coolant?

 

[TagHeuer]

once i was able to limp home coolant was pretty low. . .i let it cool down and then topped the tank off to normal cool level in the expansion tank. Started it up and let it run. . .heated up normally but then it started creeping above normal levels so i shut it down, came in and started digging through past posts. . .

 

[roverover]

Did you burp all the air out of the system?easy on a D2 blow into the res tank with the vent open close it when it is under pressure let it sit with the front end higher do it again in a few hours.

Get a kit at your auto parts store to check the coolant for exhaust gasses

 

[Roving Beetle]

Could be a stuck thermostat. But no heat in the cab says dead water pump to me since it's before the thermostat.

Now - that said, if you had head issues and lost enough coolant to get air in the system the heater could be air bound.

I agree - get a kit to test the coolant and also start looking close for simple leak.

 

[ptschram]

No, no, no.

Sadly, it is almost certainly head gaskets.

When they fail and coolant is sucked into the combustion chambers, we now have a void in the cooling system as air seeps in. As the air displaces the coolant from the heater core, we lose heat.

Shut the truck down, fill with coolant, run to op temps, look for coolant leaks at back of heads and plenum deicer. If none obvious, run combustion gas in coolant test. Prepare to remove heads, have them machined and call me for gasket set.

I am having the kid run to the machine shop to have heads refurbished if you need a set.

 

[ptschram]

Never forget that the temp gauge in a DII is not linear. It has three positions. Cold, about right and "you're fucked". It isn't a D'Arsonval gauge, it's a stepper motor with three positions.

 

[roverover]

I had assumed you checked to see that coolant was moving through the system and I am assuming that you were just letting it idle when it was overheating at the last report. They usually don't overheat at an idle with a head gasket or slipped liner and if you have air in the heater you should hear a waterfall noise behind the dash. Once you have it burped out check for leaks at the T-body heater and the heater core inside the truck (wet floor on pass side) I have had a couple with several small leaks that allowed the coolant to fall low enough that it caused an air bubble in the block and wouldn't cool proper until it was burped If there are combustion gasses in the coolant you may well have a bad head gasket.

 

[listerdiesel]

As always, check the air bleed needle in the header tank isn't blocked.

As the overflow pipe is on the engine side of the header tank, getting coolant over to the fuse box sounds a bit strange.

Peter

 

[ptschram]

They usually don't overheat at an idle with a head gasket or slipped liner and if you have air in the heater you should hear a waterfall noise behind the dash..

WTF?

I have had numerous trucks with both that I could set my watch by the overheating at seven to ten minutes after start-up.

In fact, when starting a headjob truck for the first time, I set the timer for seven minutes. If it makes it that far, I feel some degree of comfort that it is gonna be alright.

 

[singingcamel]

Id agree with PT on this one and might lean more towards slipped sleeve, once a sleeve loosens it pressurizing the coolant side, forcing all the coolant to the overflow tank, it also flows the coolant out of heater circulation, thus no heat. If you pull the heads make sure you pressurize the block just to make sure its a gasket issue and not a loose sleeve.
With the earlier post on the girgling you have a air in coolant and may be a head gasket issue or worse loose sleeve.
I hope its a eay fix for ya . Good Luck.

 

[TagHeuer]

thanks guys! . . . PT, that's what my gut was telling me but hoping for the best. . .i had to go out of town so i just dropped it off at my local shop to have him diagnose it while i'm gone and get an estimate if, in fact, its a head gasket failure. In the meantime, I'm digging through past posts to determine if its something that I'm comfortable doing. Ill be sure to contact you as soon as i know to get the parts ordered. If it does turn out to be a loose sleeve, is that something that I can address?

 

[ptschram]

Everything can be addressed, money and time.

The sleeve can be removed, holes found, ground down, tigged shut, ground down, new sleeve pressed into place, block decked and reassembled.

 

[geoff]

Hi guys. I have had my truck lose coolant and eventually overheat twice from the hose on the top of the thermostat slipping slowly off. After the second time I noticed the mounting for the hose was completely collapsed from heat/time I suppose. The plastic would just crumble. If you haven't changed your thermostat I would highly recommend it.

 

[TagHeuer]

Well, unfortunately (but not surprisingly) PT was right and the head gasket finally blew so exhaust is now entering the coolant system causing the overheating. Anyway, the mechanic has given me the "its not worth fixing. . .send her to the junkyard" speech along with an "if you insist on fixing it" quote in excess of $2,500 just to do the gaskets. . .no valve job, no machining the heads, nothing. I'm wanting to get this back up and running on my own knowing the solid information available on this site but he's got me second guessing myself. . .

 

[K-rover]

Only you can decide if its worth fixing.. That said I had my HG done with redone heads and valves for $1400 about 3 yrs ago. Obviously doing it yourself would be even cheaper, but a lot more work!

 

[riceybean]

Did my heads over a year ago, spent about 700 all told. Easy to do just takes patience.

 

[TagHeuer]

Yeah. . .i'm pretty determined to get this back up and running on my own. Just need to get through the research and mental preparation!

Is is preferable/recommended to go with a purchased set of refurbished heads or take the ones i have to a shop to be done? I wouldn't know where to start looking for someone to do this around here and I've been reading some posts about shops who don't get the heads machined correctly. PT, you mentioned sourcing them from you so i was curious if this is the better route?

 

[riceybean]

I just used the local machine shop, NAPA. Had them decked and the valves checked and re-ground if needed.

Bought the head gasket stuff from a few vendors (bputah and British Pacific) while waiting for the heads to be done.

 

[TagHeuer]

Thanks again for all the input. . . i'm resurrecting this thread as i'm finally getting ready to dig in to this effort.

One concern that i have is pre-purchasing all of the parts in preparation for a head gasket job, only to find that it is, in fact, a slipped liner. My question is whether or not I can diagnose (or negate) the presence of a slipped liner prior to digging in to the engine? I'm thinking no but wanted to ask. As indicated previously, I have had a mechanic confirm that exhaust gases were present in the coolant so he deemed this as a head gasket failure. Would a slipped liner alone result in this same finding?