Overheating After Extensive Coolant system renovation

[Houston]

My friends 1999 DII 4.0 was overheating. He had so many oil leaks and otherwise that I talked him into parting it in my driveway and spending the last 2 weekends (and some week nights) doing some work to get this thing straight.

We did the following:
New water pump and gasket
New front cover gasket
New crankshaft seal
New oil Pan gasket
New thermostat
New oil pressure switch
New timing gear and chain
New viscous fan clutch


Coolant Fill:
We refilled it and used ~3 gallons of coolant. Elevated the reservoir and opened the bleed screw... poured in coolant until it flooded out of the bleed screw steadily.

Started the truck and drove it around. It started overheating again. Stopped and let it cool then squeezed all the hoses and opened the res and bleed (with the res elevated. No air came out. Looks like the fill is correct...

Symptoms still occuring:
It will go about 5 miles and then suddenly start to overheat. It's not a immediate skyrocketting temp though. It elevates and then stabilizes, then starts climbing again. Obviously we always stop and let it cool before it leaves the "normal" bracket.

Theory:
We have changed everything. I can only come up with two thoughts.


Radiator failure or blockage:
I have literally never had a radiator failure or blockage, but if there was going to be one this truck would make sense.

It has been poorly maintained and constantly filled with non-dex coolant and straight up hose water. I know that the block channels might now be occluded... but let's start with the simpler question.

This is my leading theory and I hope I can get some feedback on it. I am going to follow him over to a value radiator shop off Shephard at around 2:00 to get the thing flushed and tested.

DOA thermostat: All of the hoses feel equally (or very close) hot. I have to suspect this because the truck doesn't just draw a straight line between cold and overheating, It's cooling, and then it's not.

The heater is blowing hot the whole time. For what it's worth.

You guys are always a great help in figuring things out. I appreciate it as I have nobody that I can do this kind of problem bouncing in person.

Un-necessary lamentation: I wish the cooling systems on our trucks weren't so prone to problems. It's a real pox on the awesomeness.

 

[lunchbox]

You didn't mention burping it. No burp = overheat.

 

[ukoffroad]

Did you do the head gaskets?

 

[Houston]

You didn't mention burping it. No burp = overheat.

Help me understand the burp. I have filled my truck after a headgasket job and I used, as I have here, the RAVE manual steps. I would really like this to not be a radiator issue.

I have read many, if not all the forum posts about coolant filling and i was under the impression that it all really boiled down (oh the puns) to the RAVE directions.

No we didn't do the headgaskets. My buddy is short on money and patience. It was a miracle that I got him to dig down to the timing chain.

 

[Jake1996D1]

My guesses in order of possibility and how I would trouble shoot it.

1. try bleeding it again - do you hear the waterfall behind the dash?
2. partially blocked radiator - you can use your hand to feel around and see if half is hot and half is cold or use a laser IR therm
3. sticking t-stat - sounds like you already figured out how to see if this is working or not

 

[Tugela]

My buddy is short on money and patience.

May I suggest you are asking the wrong question? Instead of contemplating the cause of the engine overheating, given your statement about your friend's budget and temperament the more important question should be "is a Land Rover the right car for this guy?"

The answer you're looking for may be "replace the head gaskets" but the answer he needs is "buy a Toyota Corolla."

Not trying to be a smartass, just encouraging a bigger picture examination of the situation.

 

[LRflip]

air in the line, fan clutch, blocked radiator.

your hoses are supposed to be hot, they're carrying 200 degree fluid, so even though they are insulated they're going to get hot.

try a new thermostat...I drilled a couple holes in mine to let the water bypass before it gets to operating temperature. Doesn't do much but it helps. and it still warms up plenty for the North Carolina winters.

and if you're in texas, you could just replace the tstat with a washer...the truck will warm up down there...I promise.

I wouldn't have the radiator re-cored...I took mine to have it done and they said after 2 days that it was shot and they couldn't put it back together.

mix 60/40 with distilled water/dex

make sure you get all of the air out! let it get warm then burp that shit out.

 

[Jake1996D1]

Help me understand the burp. I have filled my truck after a headgasket job and I used, as I have here, the RAVE manual steps. I would really like this to not be a radiator issue.

I have read many, if not all the forum posts about coolant filling and i was under the impression that it all really boiled down (oh the puns) to the RAVE directions.

No we didn't do the headgaskets. My buddy is short on money and patience. It was a miracle that I got him to dig down to the timing chain.

http://kidshealth.org/parent/pregnancy_center/newborn_care/burping.html


But for real. Park the truck on an incline. While running loosen bleed screw. Let it bleed for a while and give it a couple revs just to get everything circulating. Once you havent seen any bubbles come out with the coolant tighten screw and retest.

 

[Houston]

"is a Land Rover the right car for this guy?"

The answer you're looking for may be "replace the head gaskets" but the answer he needs is "buy a Toyota Corolla."

Amen, but here we are.



NOTE: I forgot to mention that it's a new Viscous fan clutch as well.

I will try the elevating front end before anything else.

Will I see the collant level drop in the Res?

This is all very odd that I havent had all these problems before. I thought I had seen everything I should never think that again.

 

[singingcamel]

I really would recommend eval of the of the entire coolant system, flushing radiator . I doubt you have air , My bet is headgaskets? slipped sleeve , bad block.

 

[lunchbox]

Open expansion tank and fill hole in radiator.

Start truck.

Turn heater and fan on high.

Let engine warm up and let the bubbles fly.

Top off coolant.

Takes 15 min.

 

[WaltNYC]

Did you refill with 100% coolant? or a mix of coolant+H2O

 

[p m]

The symptoms you're describing fit my old Classic to a tee. Two owners later, the cause was discovered to be a cracked block.

One thing you can check relatively easily - get a thick glove, and when the truck gets hot (beginning to overheat), try to squeeze the top radiator hose. If it feels rock hard, it is likely due to exhaust getting into coolant due to either blown head gasket or cracked block.

 

[LRflip]

The symptoms you're describing fit my old Classic to a tee. Two owners later, the cause was discovered to be a cracked block.

One thing you can check relatively easily - get a thick glove, and when the truck gets hot (beginning to overheat), try to squeeze the top radiator hose. If it feels rock hard, it is likely due to exhaust getting into coolant due to either blown head gasket or cracked block.

That's deceptive...my wife's old P38 would build TONS of pressure on that top hose...

its meant to be somewhat of a pressurized system so I don't feel like that's a good indicator. especially since he's already overparanoid about the worse case scenario, a stick of butter is going to feel rock hard to this guy.

 

[DarylJ]

Let's get this out of the way: coolant exhaust gas test. Go rent one from AutoZone and use it. If you've got exhaust gases in the coolant, nothing else matters at this point as you'll need head gaskets at best. And possibly much worse.

 

[Jake1996D1]

That's deceptive...my wife's old P38 would build TONS of pressure on that top hose...

its meant to be somewhat of a pressurized system so I don't feel like that's a good indicator. especially since he's already overparanoid about the worse case scenario, a stick of butter is going to feel rock hard to this guy.

HAHAH! so true..


Let the guy properly bleed the system before people start jumping to conclusions about cracked blocks or head gaskets. My truck did the same shit and it was a clogged radiator.. Nobody can diagnose the trucks issues until we have a decent baseline to start at..

 

[SGaynor]

Was it overheating before you did the cooling system work?

If not, it's likely the thermo or radiator (or air in the system).

If yes, then block/heads might be the deal.

I can't see it suddenly developing a cracked block/blown HGs if it wasn't overheating before.

 

[p m]

That's deceptive...my wife's old P38 would build TONS of pressure on that top hose...

its meant to be somewhat of a pressurized system so I don't feel like that's a good indicator. especially since he's already overparanoid about the worse case scenario, a stick of butter is going to feel rock hard to this guy.

It is a pressurized system all right, but it should not be pressurized beyond ~16-20 psi. At this pressure level, one doesn't have to have a rock climber's hand to squeeze the top hose - maybe not flat, but halfway for sure. When my Classic went from normal to hot, the hose became really rock hard - just before the coolant started to leak out from the expansion tank.

My green D1 makes the dreaded sloshing noise in the heater core, so it is not burped properly; yet it doesn't run hot and the hose is "squeezable" (don't want to draw any physiological parallels here).

Scott - the OP started with the statement that the truck was overheating before the work.

 

[crown14]

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.

 

[Houston]

Did you refill with 100% coolant? or a mix of coolant+H2O

It's 50/50