2.8L Diesel hilux help. Engine cooling system problem. (1 Viewer)

[jackboil]

my 1988 2.8L diesel hilux has these symptoms: losing some coolant with no visible leak, it is overheating quickly (10 minute drive) and the radiator cap fizzes a bit when it is opened after the engine cools. Could be head gasket but there is no exhaust bubbles in reservoir, there is no steam or smoke being blown from the exhaust when it is hot or cold, the exhaust fumes smell fine and the oil is not milky. Another note is that this all started just after i did a fuel pump overhaul due to it leaking badly. If anyone had any suggestions on what is happening that would be awesome. thanks

 

[KLF]

I know very little about diesel engines, but I can't think of a scenario where that couldn't be a leaking head gasket. Perhaps a cracked head or block. Either way, the engine has to come apart.

Blown head gaskets present themselves in many ways, but they don't always have the same symptoms. I bought my son an '89 4Runner many years ago and it ran great, but one day we noticed coolant dribbling down the side of the block.

Can you do a leakdown test on a diesel?

 

[GTSSportCoupe]

Feel the upper rad hose right after you start the engine when it's cold. Is it rock hard? If so, the coolant system is getting pressurized. Does the reservoir get really full or overflow? Is there air in the cooling system? These would all point to a cracked cylinder head or head gasket issue.

If you are loosing coolant but don't have the issues above, it could be a subtle leak you have not found yet. Carefully check all heater hoses, rad hoses, heater core, reservoir etc. Make sure you have a good radiator cap.

 

[advlars]

Sounds like a head or headgasket to me... And I get the impression the headgaskets tend to outlast the heads on these trucks.

You can make leakdown tester for this engine by pulling the hose off a diesel compression tester with an m10x1.25 glowplug fitting and hooking it up to an air compressor. Get the engine up to temp, then manually put your engine to TDC and pressurize the cylinder with compressed air via the glowplug hole. Do this for each cylinder. If you see or hear bubbles in the radiator fill cap then thats your problem.

Alternatively you might be able to to do a radiator test and find a leaky fitting elsewhere. Most auto parts stores rent the tool to do that.

 

[roscoFJ73]

I would check the thermostat 1st. Has the radiator been flushed or rodded?
Do the hoses maintain pressure overnight?

Which engine is it? 2L, 3L?

 

[advlars]

Which engine is it? 2L, 3L?

2Ls are 2.4liter and 3Ls are 2.8

Another thought I had:
I was mysteriously losing coolant on my 2lt because of a leaky connection where my coolant reservoir hose attached to the overflow nipple. When the engine heated up it would push coolant out into the reservoir and then suck air back in through the leak when it cooled down. Perhaps if your coolant fill cap is bad its pushing out the coolant when its hot and creating a vacuum. That fizz you hear when you open it up could be air rushing into the radiator to take the place of the missing coolant.

 

[roscoFJ73]

2Ls are 2.4liter and 3Ls are 2.8

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Yes, I know this, but the 3L wasn't available in 1988 to my knowledge.