Uh oh! Blown Head Gasket?

[Radius]

Hi everyone!

So after 2 years of owning my Clark C500S60, I've finally gotten to the point where I am starting to use it quite often.

I checked the oil the other day and it's gray. So then I checked the coolant and it's low.

If I let the truck sit for a day and check the oil, then it looks ok. It's only after it has run for 15 minutes or so that the oil is gray.

I pulled the oil fill cap and looked inside with a flashlight and I can see rust on the rocker arms. So moisture of some sort is definitely ending up inside the crankcase.

When considering the low coolant, a leaking head gasket is the obvious suspect.

However, since I don't know these motors very well, is there another common problem that could manifest itself as a blown head gasket? Are these engines known to crack the head or anything like that? I found a head set on ebay for $125 so that's not bad.

I need the truck really bad right now even though I know I need to fix this soon. The engine is still running well with no knocking, etc.

Can I warm it up, change the oil and filter and run it with a loose radiator cap for a bit longer like this before I fix it?

Any other gotchas to be concerned about when attempting this job?

Oh! I almost forgot. This particular truck has been converted to CNG, if that matters.

Thanks,
Michael

 

[Radius]

Errr.. I meant to say the truck has been converted to propane. Sorry about that.

 

[overworked]

When its cold , crack the oil drain plug a few turns and see if coolant comes out, then disconnect the coil white and crank it over, pull spark plugs and see if wet with coolant.

 

[Radius]

When its cold , crack the oil drain plug a few turns and see if coolant comes out, then disconnect the coil white and crank it over, pull spark plugs and see if wet with coolant.

Good plan, I will do that..

I have also read that if a propane powered truck is not run long enough to heat up, then water vapor from the combustion process will not have a chance to burn off. I am guilty as charged here as I have a tendency to use the lift for the 5 or 10 minutes I need it for then shut it off.

I didn't know that using propane as a fuel would results in a lot more water as a combustion byproduct versus gasoline and diesel.

Michael

 

[lantraxco]

Sitting without running the engine will condense water over time, a LOT of water if you're in a colder, wetter climate like we are and yes, running on propane doesn't help. Getting it just warm enough to suck cold wet air in as it cools is kinda the perfect storm. One thing you might consider, before changing oil pull a sample and send it in for testing, any equipment dealer should have this service, I know CAT does and usually Deere and CASE, on the label mention you're looking for glycol. The glycol antifreeze will strip the bearing material off the rod, main, and cam bearings. If it's just water, after you change oil and filter, run it a few hours and do it again.

 

[Radius]

Sitting without running the engine will condense water over time, a LOT of water if you're in a colder, wetter climate like we are and yes, running on propane doesn't help. Getting it just warm enough to suck cold wet air in as it cools is kinda the perfect storm. One thing you might consider, before changing oil pull a sample and send it in for testing, any equipment dealer should have this service, I know CAT does and usually Deere and CASE, on the label mention you're looking for glycol. The glycol antifreeze will strip the bearing material off the rod, main, and cam bearings. If it's just water, after you change oil and filter, run it a few hours and do it again.

Good idea.. I will check into that. I think there are plenty of places you can find on the net that will do it too and eliminate some markup.

And yes you are right, the cold damp air - especially in winter time - and infrequent use can result in a lot of water in the crankcase. Plus operator error in not letting it warm up enough when using it doesn't help either.

I guess the thing that made me assume head gasket was the low coolant. But the oil analysis will tell me that.

Speaking of oil change, does anyone know the NAPA oil filter number for this machine? I tried to look online but NAPA does not list Clark trucks. Only Hyster and a couple others. The closest Clark dealer is over 100 miles from me.

Thanks,
Michael

 

[overworked]

Yes you can see milky oil if not run much, just might have to change oil at 50 or 100 hours instead of 250. Been down that road. But you said you are loosing coolant. I like lantraxco's post about oil sample looking for glycol.

 

[Radius]

Yes you can see milky oil if not run much, just might have to change oil at 50 or 100 hours instead of 250. Been down that road. But you said you are loosing coolant. I like lantraxco's post about oil sample looking for glycol.

Man, I'd be lucky to get even 50 hours a year on this machine. Yes, I use it, but it comes in spurts. I might use it for a couple of hours a day for a couple of days, then not touch it for 3 months. Or use it for 10-15 minutes every week or so. Just depends on what I have going on.

I guess I will do the oil analysis thing, change the oil and filter a couple of times and then keep an eye on it.

Michael

 

[overworked]

Crack the drain plug loose first, if there is antifreeze coming out first you won't need oil analysis.

 

[Delmer]

and eliminate some markup.

The kit from Cat is/was $11/sample. You won't find it cheaper unless you have to drive a ways to a Cat dealer.

I don't know about the others, but I have no idea what engine or age this thing is, that might help a bit.