Power Loss & Overheating

sbk · **Posted:** Wed May 29, 2019 11:15 pm

Could oil sludge in the intercooler cause the engine to overheat? I wouldn't think so but obviously I'm no expert with these particular engines.

GordnadoCRD · **Posted:** Thu May 30, 2019 12:09 am

sbk wrote:

Could oil sludge in the intercooler cause the engine to overheat? I wouldn't think so but obviously I'm no expert with these particular engines.

Not significantly.
It can reduce the efficiency, causing the intake air temperature to be higher than normal, but not to the extent you're seeing.
Mostly it just makes a mess.

iakj11 · **Posted:** Thu May 30, 2019 8:51 am

sbk wrote:

iakj11 wrote:

These observations along with the P1252 may indicate a bad boost pressure solenoid. Cheap part to replace, I think.

Is this the item you're talking about? https://www.idparts.com/vacuum-solenoid ... -3211.html

Yes. Before you order it, try the bypass procedure described in the post I linked previously. Let us know what happens.

TKB4 · **Posted:** Thu May 30, 2019 10:12 am

Just as you did, I suspected that the radiator was probably not the cause. However, ,just because no residue in it and water flows through it doesn't mean a significant number of the passages couldn't be clogged but you should see some indication of that looking in it such as crusty stuff or whitish grey crystal/sludge at the openings of the cross tubing. After all the cooling is accomplished by flow through the small tubes not just the ends and hoses.

I suppose you could get at least an idea of whether or not the water pump is functional by removing the ASD relay so engine cannot start and turning the engine over with the radiator hooked to hoses not necessarily reinstalled and remove supply heater hose near the bracket on passenger side of valve cover and see how much flow and pressure it seems to have.

Unless you are 100 % sure the coolant was boiling with a functional radiator cap its also possible that the temp gauge could be affected by a wiring short etc that may be from wiring that also affects the vacuum solenoid voltage but that should cause low voltage not high and not really affect the sensor resistance etc.

If I were you I would replace the solenoid after the bypass check if bad and see how it does or bite the bullet and replace water pump again at least check it and replace the solenoid. Perhaps the overheating damaged a wire to solenoid or solenoid itself.

I keep thinking that both didn't happen at exactly the same time unless caused by each other. An infrared temp gun could also give you an idea of engine temp and roughly correlate to the gauge.

sbk · **Posted:** Thu May 30, 2019 12:00 pm

TKB4 wrote:

Just as you did, I suspected that the radiator was probably not the cause. However, ,just because no residue in it and water flows through it doesn't mean a significant number of the passages couldn't be clogged but you should see some indication of that looking in it such as crusty stuff or whitish grey crystal/sludge at the openings of the cross tubing. After all the cooling is accomplished by flow through the small tubes not just the ends and hoses.

There's not the slightest hint of any corrosion. No crystals anywhere. No sediment of any kind comes out. Drained coolant looks like it did when it came out of the jug, (mixed with distilled water, of course).

TKB4 wrote:

I suppose you could get at least an idea of whether or not the water pump is functional by removing the ASD relay so engine cannot start and turning the engine over with the radiator hooked to hoses not necessarily reinstalled and remove supply heater hose near the bracket on passenger side of valve cover and see how much flow and pressure it seems to have.

I have the front of the Jeep off, so I'm going to take the timing cover off and check the water pump. Maybe I got a bad one like in the thread that flash7210 posted.

TKB4 wrote:

Unless you are 100 % sure the coolant was boiling with a functional radiator cap its also possible that the temp gauge could be affected by a wiring short etc that may be from wiring that also affects the vacuum solenoid voltage but that should cause low voltage not high and not really affect the sensor resistance etc.

I'm 100% sure that the coolant was boiling and that the radiator cap was holding pressure. No leakage at all. I assume that means it was functional. Is that correct?

sbk · **Posted:** Thu May 30, 2019 2:40 pm

Took the water pump inlet off so I could feel if it was turning. The impeller turns right along with the engine, so I think it's fine. I'm stumped. Anybody want to buy this thing?

flash7210 · **Posted:** Thu May 30, 2019 3:55 pm

Quote:

I'm 100% sure that the coolant was boiling and that the radiator cap was holding pressure. No leakage at all. I assume that means it was functional. Is that correct?

If the radiator cap was holding pressure, then the coolant was NOT boiling.

If the coolant was boiling, then the radiator cap should release the pressure into the overflow side of the reservoir tank.
If the radiator cap does not relieve the pressure of a boiling liquid, that liquid WILL find a violent means of escape.

sbk · **Posted:** Thu May 30, 2019 6:35 pm

flash7210 wrote:

Quote:

I'm 100% sure that the coolant was boiling and that the radiator cap was holding pressure. No leakage at all. I assume that means it was functional. Is that correct?

If the radiator cap was holding pressure, then the coolant was NOT boiling.

If the coolant was boiling, then the radiator cap should release the pressure into the overflow side of the reservoir tank.
If the radiator cap does not relieve the pressure of a boiling liquid, that liquid WILL find a violent means of escape.

I guess I'm not sure then. The coolant was boiling, without a doubt. No coolant was escaping from the tank or anywhere else however. Maybe I'm misunderstanding how this system works. As I mentioned before, I'm primarily used to the old mechanical Cummins engines. Don't even need a radiator cap at all on those, other than to keep crap out of the radiator. Is it really possible that a bad radiator cap could cause one of these to overheat that easily?

flash7210 · **Posted:** Thu May 30, 2019 7:10 pm

sbk wrote:

flash7210 wrote:

Quote:

I'm 100% sure that the coolant was boiling and that the radiator cap was holding pressure. No leakage at all. I assume that means it was functional. Is that correct?

If the radiator cap was holding pressure, then the coolant was NOT boiling.

If the coolant was boiling, then the radiator cap should release the pressure into the overflow side of the reservoir tank.
If the radiator cap does not relieve the pressure of a boiling liquid, that liquid WILL find a violent means of escape.

I guess I'm not sure then. The coolant was boiling, without a doubt. No coolant was escaping from the tank or anywhere else however. Maybe I'm misunderstanding how this system works. As I mentioned before, I'm primarily used to the old mechanical Cummins engines. Don't even need a radiator cap at all on those, other than to keep crap out of the radiator. Is it really possible that a bad radiator cap could cause one of these to overheat that easily?

Every car, truck, and tractor built since my dad was born (and probably before then) has a pressurized cooling system.
Pressure raises the boiling point of the liquid. Up to a point that is.
The CRD has a 16psi cap. As the system heats up and expands, pressure increases.
If it gets above 16psi the cap will release the pressure.
Thats why the cap has the springy thing in it.
And when the pressure is released, the liquid boils.

Straight water boils at 212F at sea level (14.7 psi).
Add 16 psi to that a water wont boil until 250F (30 psi).
Adding coolant to the mix and the boiling point will be raised a few more degrees.

I dont know how high in mountains of WV you were, but as you go up in altitude air pressure decreases and so does the boiling point. Usually only a factor when crossing the rockies. Not so much the Appalachians.

sbk · **Posted:** Thu May 30, 2019 8:12 pm

flash7210 wrote:

Every car, truck, and tractor built since my dad was born (and probably before then) has a pressurized cooling system.
Pressure raises the boiling point of the liquid. Up to a point that is.
The CRD has a 16psi cap. As the system heats up and expands, pressure increases.
If it gets above 16psi the cap will release the pressure.
Thats why the cap has the springy thing in it.
And when the pressure is released, the liquid boils.

Straight water boils at 212F at sea level (14.7 psi).
Add 16 psi to that a water wont boil until 250F (30 psi).
Adding coolant to the mix and the boiling point will be raised a few more degrees.

I dont know how high in mountains of WV you were, but as you go up in altitude air pressure decreases and so does the boiling point. Usually only a factor when crossing the rockies. Not so much the Appalachians.

Not sure what to tell you other than that I could see the coolant was bubbling in the tank and I could hear it bubbling in the radiator and it wasn't leaking out anywhere. I can't imagine the elevation had much to do with it but I suppose it may have been a factor. I did cross the eastern continental divide while test driving it after putting the thermostat in.

gollygeemister · **Posted:** Fri May 31, 2019 11:06 pm

Now it sounds like you have a severe head gasket leak. With combustion gasses rushing through the coolant passages of your head, displacing coolant, it overheats with the slightest load. Sound like you're even losing compression and down on power.

TKB4 · **Posted:** Sat Jun 01, 2019 9:30 am

I may have missed it did you do the test I suggested for the head gasket before removing the radiator etc. ?Unfortunately if you didn't you can't do it without a sealed cooling system or basically hooking up radiator again. Another course would be to pull head replace gasket do the ARP s check head replace exhaust valves and rockers and also address the Turbo issue. Then hopefully semi bullet proofed engine. I use the word semi because all of us CRD owners for any significant mileage know there is no such thing !!!!

sbk · **Posted:** Sat Jun 01, 2019 2:08 pm

TKB4 wrote:

I may have missed it did you do the test I suggested for the head gasket before removing the radiator etc. ?Unfortunately if you didn't you can't do it without a sealed cooling system or basically hooking up radiator again.

Unfortunately I had already removed the radiator by the time you posted that. I took the coolant inlet off of the back of the water pump and turned the engine over by hand. I could feel the impeller turning and could not, at least with my fingers, stop it from doing so, so I'm pretty sure the water pump is good.

TKB4 wrote:

Another course would be to pull head replace gasket do the ARP s check head replace exhaust valves and rockers and also address the Turbo issue. Then hopefully semi bullet proofed engine. I use the word semi because all of us CRD owners for any significant mileage know there is no such thing !!!!

We'll see what it looks like once I get the head off.

TKB4 · **Posted:** Sun Jun 02, 2019 1:31 am

you may well not be able to see anything except maybe some antifreeze in a cylinder. The head gaskets are three layers of steel and a leak is often between the layers leaving no definite evidence just by looking. However if you remove head you will probably find the exhaust side head bolts around cylinders 2 and 3 area require much less torque to remove. BTW I would not use 0w-40 Mobil ! oil I personally use 5w-40 Mobil 1 turbo-diesel oil or sometime same weight of T6 Rotella. There are many opinions in other threads about this.

sbk · **Posted:** Sun Jun 02, 2019 9:25 am

TKB4 wrote:

you may well not be able to see anything except maybe some antifreeze in a cylinder. The head gaskets are three layers of steel and a leak is often between the layers leaving no definite evidence just by looking. However if you remove head you will probably find the exhaust side head bolts around cylinders 2 and 3 area require much less torque to remove.

I'm just hoping it's the head gasket and not a cracked head.

TKB4 wrote:

BTW I would not use 0w-40 Mobil ! oil I personally use 5w-40 Mobil 1 turbo-diesel oil or sometime same weight of T6 Rotella. There are many opinions in other threads about this.

What don't you like about 0W-40? I used it just because that's what the manual recommended. It's not what I use in my other diesels.

sbk · **Posted:** Mon Jun 03, 2019 12:18 pm

Got the head off last night. I'm reasonably sure it was the head gasket, although, as TKB4 said, it's tough to tell for certain. The front injector was totally coated in oil. I don't see any cracks in the head but I'm going to clean it good and make sure. I've decided to sell it, either whole or in parts, so if anyone is interested, let me know. I need a vehicle that's easier to get parts for locally. Is it ok to post for sale ads on this site? I saw a few and didn't see anything prohibiting it but I know some forums are picky about that.

WWDiesel · **Posted:** Mon Jun 03, 2019 12:24 pm

sbk wrote:

Got the head off last night. I'm reasonably sure it was the head gasket, although, as TKB4 said, it's tough to tell for certain. The front injector was totally coated in oil. I don't see any cracks in the head but I'm going to clean it good and make sure. I've decided to sell it, either whole or in parts, so if anyone is interested, let me know. I need a vehicle that's easier to get parts for locally. Is it ok to post for sale ads on this site? I saw a few and didn't see anything prohibiting it but I know some forums are picky about that.

Best to post "For Sale" items here:
Jeep Parts & Vehicles For Sale by Members of LOST JEEPS
viewforum.php?f=35

Power Loss & Overheating

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