Overheating After Extensive Coolant system renovation

[Jake1996D1]

I really feel like we're having two different conversations, so I'm just going to stop here.

Yea but you didnt quote the second half of what I said. plus he doesnt state if it is highway or stop and go driving which would make a huge difference in how the temp spikes..

 

[Houston]

Yea, I wouldn't take what I said personally considering I don't know you personally.

What I am trying to say is that when I think there is something wrong with my truck, I am overly sensitive to every noise and slightest movement of the gauges. I call it "Roverchondria".

This may be a different circumstance since it's not your truck but, I know that's how I would be. Not calling you a rube.

Excellent- and I agree. I know what it's like to be sensitive to every waggle and wiggle.

 

[Houston]

Shit- I guess I also forgot to mention a new t-sat in the OP. yea that's been done.

Radiator seeme to be uniformly hot with the hand test.

 

[Houston]

I think we're going to spring for the tester. It's the last reasonable thing to do before calling it.

 

[slanginsanjuan]

The rad shop could 1) test your radiator and 2) pressure test your system. You'd find out everything in an hour.

I am very surprised how fast my temps rose with an air bubble on the last refill. I assume they would have kept going above 210 if I let it. There was a waterfall effect. Properly bleeding solved that immediately.

I did an inline tstat mod with a bleed valve. I park on an incline and cover the expansion tank with a clean fabric. Open the bleed valve and blow air through the expansion tank until water comes up and out the valve. I might do it a couple times and then cap it. Top off expansion tank and no waterfall or overheat.

Ridiculous how the plastic t and lower radiator hose plastic W (or whatever it is) and the hard line expansion tank hoses deteriorate, crack and can lead to colossal failure. Also the throttle body heater is going to leak as well.

You're shooting in the dark if you don't have a temperature gauge.

 

[singingcamel]

We are talking about a D2 here folks, some of you are preaching D1 tactics.

I have done this a couple thousand times if I have done it once. What I do:

-Remove the bleed screw.
-If the radiator is empty or mostly empty, pull the upper hose off and fill the system through the reservoir until coolant starts to come out the radiator neck, then stick the hose back on.
-unclip the plastic line from the radiator from the battery box, and release the clip holding the reservoir to the truck. Fill it to a little above the line and elevate it up towards the bottom of the hood. As gravity forces the coolant out the bottom and into the rest of the system, the (most of) air will come out of the bleed hole in the upper hose. Make sure the reservoir tank does not go empty, the volume of that elevated fluid is what is providing the "forced" bleeding of the cooling system.
-Eventually the coolant is going to come spurting out of the hole, at this point blurt out "old faithful!", and reinstall the bleed screw. Don't stick it in there the very instant you see it coming out, let it get a good steady stream going, you want to make sure you get as much air out as you can.
-Refit the expansion tank/reservoir and add coolant to the line if needed. Leave the cap OFF, and start the truck. Let it run to operating temperature, keeping an eye on the coolant level in the reservoir, add if needed, do not install the cap. Of course keep an eye on the gauge.
-Once it is warmed up, and you are sure the thermostat has opened, rev gently to 3000rpm and then gently let it come back to idle. Do this 3 times. Any percolating in the reservoir is air working itself out of the system and escaping "to atmosphere" via the uncapped tank. This is the air that causes the waterfall sound in the heater core if you don't get rid of it.
-Let it idle a couple more minutes, and shut it down. Let it cool down to ambient temperature (or as close to it as you have time to wait) and if needed, add coolant to the reservoir. NOW you can install the cap. Road test and see what happens.

If you hear the noise in the dash/heater core, don't worry you just need some more practice, drive it anyway- you need to know if it is gonna overheat when working under a load. If it goes a few miles under normal driving then spikes, probably head gaskets.

Also beware not all head gaskets fail the same. I had one a while back that made some bad noises when I got it started after being parked for a few months, and the reservoir was dry. Well, before I parted it out, I had to know for sure if the engine was bad, so I filled/bled the system, checked the fluids, and it quieted down. On the spur of the moment I decided to go for a drive and forgot to reinstall the cap. Drove around for a half hour, about 15 miles total around town, and the truck was running GREAT. It was quiet, had plenty of power, no misfires at all, I had a smile on my face. Got back to the shop and popped the hood, found the cap and stuck it back on. Now of course I have to redo the test drive... poor thing makes it about a mile and dies in the middle of the highway. Immediately I form my suspicions, and given the circumstances thus far, have a good laugh about it. As I coast to the median I try restarting it, nothing. Spins like a top but wont hit a lick. Now I am convinced its a massively fucked up HG or a bunch of loose liners and the cylinders got washed down with coolant as soon as it built pressure. I unscrewed the cap, and on the last thread, it shoots out of my hand, bounces off the hood, then hits me square in the nose. Fuck it. I jumped in, spun it till the cylinders cleared and the plugs dried out, at which point it fires right up and I proceed to flog it all the way back to the shop. Eventually I tore it down, someone had done the head gaskets and "cleaned" too much off the block which led to eventual, and catastrophic, failure. No cross contamination between coolant and oil, and the cylinder pressure wasn't pushing all the coolant out of the uncapped tank, but once the cooling system got up to pressure it washed down the cylinders. Probably would have been fine in a demo derby car, but I couldn't use it.

I've had more block issues with d2 s than d1 s..i'd take a gems any day.

 

[Houston]

UPDATE:

Got the exhaust gas tester and after 3 tests we never received a reading that indicated exhaust gasses present in the coolant.

Next step: remove the thermostat and test it in hot water.

 

[Jimmy]

Hmmmm... haven't seen anyone suggest the belt was installed incorrectly yet. If the water pump is turning in the wrong direction, they're going to be problems.

While I can't see how it is possible... have read about it on one of the LR forums out there.

It's a freebie to check.

 

[crown14]

Hmmmm... haven't seen anyone suggest the belt was installed incorrectly yet. If the water pump is turning in the wrong direction, they're going to be problems.

While I can't see how it is possible... have read about it on one of the LR forums out there.

It's a freebie to check.

It is pretty easy for someone who isn't familiar with the routing to install a D1 belt incorrectly (about 3 different ways) but I am not sure you can do it on a D2/P38. But good idea, I am going to try that later just to see if it can be done.

 

[group captain mandrake]

Hmmmm... haven't seen anyone suggest the belt was installed incorrectly yet. If the water pump is turning in the wrong direction, they're going to be problems.

While I can't see how it is possible... have read about it on one of the LR forums out there.

It's a freebie to check.

I saw something like that once, wasn't a Disco, but it was funny cause the guy that did it was an ass.

That reminds me of a funny story. I had a do-it-your-selfer customer come into my shop years ago asking me about an overheating problem on his Suburban. I can't remember the specifics, but I think I told him he could have a fan clutch problem. So he comes back a couple of days later all pissed off at me because I gave him the wrong free diagnosis when I hadn't even seen his truck. It was overheating even worse than before. So I go to his house to look at the truck. I'm standing in front of it when he starts it and I immediatly get buffeted by the fan blowing out the front of the truck, my shirt was blowing around like I was riding a motorcycle. I can't remember exactly what he did but I think he got a boneyard clutch & fan that was the wrong-rotation.
It was funny, I guess you had to be there.<!-- / message --><!-- sig -->

 

[mr_ed]

Are you calling your temps off the dash temp guage, or do you have an aftermarket, mechanical temp guage? I ask because I recently dealt with this very thing in an 87 Samurai Tin Top. I know it's not a D2 but here's what I had: Head gasket began a minor leak (could smell coolant in the exhaust). Replaced head gasket and checked for straight block/head. All good. Get it back together and it still overheated. Temp guage would hang out like usual until the engine started coming up to temp, then the guage would just keep going all the way to the top peg.

I replaced EVERYTHING in the cooling system, literally (which in a Samurai is not the financial nightmare it sounds like haha) and it still did this.

Went to autozone, spend $30 on a mechanical temp guage and tapped it in upriver of the t-stat. It had been cooling fine the entire time, but the electronic guage was cleverly lying to me.

Could be worth a shot....

Ed

 

[mr_ed]

I saw something like that once, wasn't a Disco, but it was funny cause the guy that did it was an ass.

"Originally Posted by group captain mandrake
That reminds me of a funny story. I had a do-it-your-selfer customer come into my shop years ago asking me about an overheating problem on his Suburban. I can't remember the specifics, but I think I told him he could have a fan clutch problem. So he comes back a couple of days later all pissed off at me because I gave him the wrong free diagnosis when I hadn't even seen his truck. It was overheating even worse than before. So I go to his house to look at the truck. I'm standing in front of it when he starts it and I immediatly get buffeted by the fan blowing out the front of the truck, my shirt was blowing around like I was riding a motorcycle. I can't remember exactly what he did but I think he got a boneyard clutch & fan that was the wrong-rotation.
It was funny, I guess you had to be there."

Haha that is funny! Make it idiot proof and someone will make a better idiot I guess

 

[KyleT]

couple of things.

NEVER remove the bleed screw. take the hose off of the radiator and fill it that way, then fill the reservoir. chances are the bleed screw will break on you and you just bought a new top hose...
to fill:
Rev it at 2500-3000 until the fan starts to blow hot air/you can see the coolant suck down in the reservoir. whilst revving, slowly crack the coolant cap, if the level rises, shut it quick. do this until you can loosen the cap and the level doesn't rise. add coolant until it is at the level you want. cap it then let off the revving. I can do it one manned, but it can help to have someone sit in the truck.
this will NOT work if there is excessive exhaust gas blow by, it just sprays out.

I will always check it again the next day to be sure. I have done hundreds this way and have NEVER had to add coolant and have NEVER had one come back low (unless there is an unrelated problem lol) or overheat on me.

have also seen gauges not work, go out, sensors crap out ect... at least borrow a scan gauge or something and see if your ecu is seeing the coolant temp.

hoses should be firm at times, but not hard or ballooning.

 

[salvvia]

burn that Mother efer to the ground. and get a d1. or just go nuts and put a 4,2 ora gems in it

 

[stu454]

Go home, you're drunk. This thread has been dead for three years.

 

[rovercanus]

It's the hub.

 

[discostew]

Or a wire

 

[stu454]

Should've used a Yeti. They keep things cool.

 

[discostew]

fuckers probably out brake checking discos cause we didn't help him in time

 

[salvvia]

454 your awful worried about this thread since its been dead , getting all bold and having diareah off the mouth maybe you need a baby wipe