Hilux 4x4 Forum

Hello.

Long time no write about anything here. I've been doing well with the 1999 Surf. It has 232k+ km on it now. The 4 cyl has been banging along fine. But all of a sudden I'm losing antifreeze (no drips to be found in engine bay). Filling with water right now. The fluid seems to be coming out the tailpipe because I have whitish emission there, so am aware it could be a head gasket or, as someone told me, maybe valve stem seals. I'm in Moz so choosing repair option is difficult. Driving it somewhere, i.e. Nelspruit could be dangerous to overall health of engine (if no piston or ring damage). However, I'm not particularly keen on paying to crack it open here and find it needs extensive work and then I'd have to take it to SA anyway.

How do I diagnose valve stem seals versus head gasket? Can you know this without disassembling?

Wondering with all the km on it, if it has to be cracked open for head gasket and/or piston work, should I do some sort of work on it while open to set it up for a longer haul without major problems (I know that's difficult to assume but I'm willing to take a shot at averting a problem if it's reasonable probability)? Or if it turns out to be valve stem seals would there be something to do while head is off? A modification to improve the engine?

Thoughts and creativity/upgrade(if any) thoughts are welcome.

Thanks.
Dave

Hi David, yes, it has been a while since you've poked your head in here.

Firstly, I'm not familiar with the head of a 3RZ, but I cannot see how you would be losing coolant through a valve stem seal. If the coolant is being lost through the motor, then the most common cause is indeed the head gasket. Some motors have a water passage through the inlet manifold and the manifold gasket could also be the culprit in such case. Then there's the possibility of a cracked head or block.

With a failed head gasket or a crack, you would in most instances be loosing coolant through the radiator overflow as compression gasses are forced into and over-pressurise the cooling system. An exception would be if the crack is in the head between a water gallery and a port. If it's in the exhaust port it will obviously not pass through the motor.

First thing I would do is to pull the plugs noting which cylinders they came out of and examine them. If there is water passing through a cylinder the plug will be almost free of any carbon, clean so to speak and in some instances have that whitish residue you speak of, depending on what additives are present in the coolant. The plug could also show erosion of the metal.

That should give you an idea if it's an inlet port crack (or inlet manifold gasket if your motor has a water gallery through the manifold. If the plug indication is positive, you might do some erosion damage to the valves over time and a long trip might not be the bast option. An eroded plug is an easy replacement, but valves are not You could remove the inlet manifold to examine for the signs of leakage in the port or through the gasket (if there is a water gallery), of the cylinder showing positive signs.

As far as the motor goes, 230 thou Km is nothing for those motors and opening doesn't warrant doing extras except maybe valve stem seals, but if it's the head that's cracked, then you're going to do that anyway.

Hoping it's not the head.

Can anyone tell me the wrench size needed to extract spark plugs from a 3RZ engine? I'll pick up the wrench before I return to Moz.
Thanks.
Dave

Not sure of the plug socket size, but it should be easy enough to check when you go buy one.

Did you get to the bottom of your coolant loss?

It will be 5/8'' or 13/16''

Get the sparkie socket(s) alone so you can use them with your 1/2'' drive socket set and extensions.

Thank you for thoughts and answers. Sorry it's taken a while to get back to the thread. I didn't explain but I was traveling in US due to my father-in-law's death. We were caught up in all the family affairs and traveling. I returned to Moz and got the Surf to Nelspruit this past week. Determined beforehand we didn't have any major leak internally. But probably something intermittent. When they cracked it open it looks like it could be that the head warped a little. One plug had no carbon build up, I think it was the second from the front. They will send it to Joburg to have it cold and hot tested to see about cracks...which is one theory that there is a slight crack when engine is cool and when engine warms up the crack closes off. But could also be similar dynamic with the warp situation. The head gasket was in very good shape. There was a lot of rust build up inside the water ports. This may have contributed to an overheat situation.

The head, if repairable, will be reconditioned and put in good order. I am planning to do a stage one upgrade at Steve's Auto Clinic at same time - Unichip Q and exhaust improvements. That should help it along quite nicely. Will report on what happens as it goes. Thanks for inputs guys.

Thanks for the feedback David. Will be interesting to hear what is actually found to be the case.