Pressurized Coolant?

Does your Mitsubishi L300 make a strange noise? Need wheel alignment specs?
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WestCoastr
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Pressurized Coolant?

Post by WestCoastr »

Hey guys,

I'm thinking I have a cracked head (92 4D56).

I noticed some coolant leaking after some big trips this last summer. Nothing major but I can't seem to find the culprit. I finally did the ole fire it up with the rad cap off and sure enough Rad fluid shot to the roof followed by some smoke once I cut the engine. I did find a couple leaky coolant lines heading to the tranny but nothing major. It doesn't loose much coolant, has no overheating problems, no signs of coolant in the oil, and it does shoot a lot of smoke on start up. I'm weeks away from just tearing it down to the block and throwing a new head on. Just looking for some confirmation this is a head or head gasket issue? or any other ideas?

Thanks for your input in advance.
sk66
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Pressurized Coolant?

Post by sk66 »

Sounds like head to me...
Steven
1991 L300
Harrisburg, PA
Ralph in Winnipeg
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Pressurized Coolant?

Post by Ralph in Winnipeg »

Coolant is definitely under pressure hence the warning signs on the rad cap saying don't open when hot. So coolant spraying out is normal under those circumstances. I'd fix or replace the leaking lines and keep an eye on the fluids. What kind of smoke at start up? If it's billowing white smoke, coolant is leaking into the cylinders.

Ralph in Winnipeg
WestCoastr
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Pressurized Coolant?

Post by WestCoastr »

Thanks for the reply..

It's defiantly billowing white smoke .. it takes out my whole neighborhood for about 5 mins, but only occurs during cold start. It seems I loose a lot of coolant through the overflow as I often hear it bubbling when I shut it down.
helibrian
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Pressurized Coolant?

Post by helibrian »

You can always turn your rad cap on 1/2 way and drive it like that. This way it doesn’t pressurize your system.
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Growlerbearnz
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Pressurized Coolant?

Post by Growlerbearnz »

White smoke (cold, with a pungent diesel smell) on cold start is incomplete combustion, and is fairly normal when it's cold- but might be worse than usual if your head is cracked, reducing compression and/or allowing coolant to leak into the cylinder(s).

White *steam* (warm, sweet-smelling) is a coolant leak and will only show up once the engine's hot, but if there's enough coolant leaking to cause visible steam you'd cook the engine within minutes.

Bubbling out the radiator when the engine is cold is a fairly clear sign that the head or block is cracked, or the gasket has gone.

Check your oil filler cap for mayonnaise- if coolant is getting into the oil, you don't want to run the engine until it's fixed.

The heads usually crack between the valves, and the cracks can be very difficult to spot. Even if you think it's the head gasket and can't see any cracks, have the head crack tested just to be sure. I've made that mistake and having to remove the head a second time isn't fun.
Nothing says "poor workmanship" more than wrinkles in the duct tape.
WestCoastr
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Pressurized Coolant?

Post by WestCoastr »

Hey,

Thanks for everyone's input. Looks like I'm pulling the head. Just need to find some shelter to do it now.. :-D

Happy Holidays
WestCoastr
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Pressurized Coolant?

Post by WestCoastr »

I thought it would be appropriate to give those that helped out an update. I finally... got the head off today. Unfortunately, I had to drill off the head of a head bolt and I'm just letting that sit over night w/ some penetrating lube before I try and get the rest out.

Looks like it was a head issue. I'm not 100% sure where exactly as the gasket looked pretty good, but cylinder two had this gummy build up that I'm thinking was coolant. The head bolt that is being stubborn was right by that cylinder. :?
Ole head 2.jpg
Ole head 2.jpg (124.27 KiB) Viewed 2273 times
It almost looks like there was a bit of damage by the fuel inlet.

On another... On inspection of the turbo I found a bit of oil by the spindle thingy. Not a whole lot and the axle had little to no play but there is quite a bit of soot or gunk on the inlet side of the head. Is this a concern? Oil from the Turbo? The metal oil return line seemed to be leaking a fair bit as well.

Lastly, any input on proper care of the fuel injectors before I swap them to the new head would be much appreciated. I've started removing and just need to find a 22mm socket to get out what i think is the last part. I just heard it is very easy to damage these and didn't want to add them to the shopping list.
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Growlerbearnz
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Pressurized Coolant?

Post by Growlerbearnz »

Is that a crack I see there, running between the two valves? Give that area a scrub.

The injectors should come out as one piece (once you've removed the fuel return rail). Best not to disassemble them. The delicate part is the tiny nub sticking out the injecty end- it's the pintle, it's both a high-pressure valve and creates the spray pattern. It bends easily (but imperceptibly) if hit on anything.

Fitting a set of rebuilt injectors is a good idea, but easy to do later if you're on a budget.
Nothing says "poor workmanship" more than wrinkles in the duct tape.
WestCoastr
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Pressurized Coolant?

Post by WestCoastr »

Unfortunately, only one injector came out in one piece.
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