mikaelm123

Hey guys first time poster but I have definitely enjoyed lurking around the forum for a while. I picked up a 91 4runner manual 3vze with 205k miles about two months ago. I did some minor maintenance/replacing and everything was running fine till the other day. I am driving home and I noticed extra exhaust coming out/whitish smoke. I checked the coolant level and the oil cap and there seemed to be no loss of coolant or chocolate milk.

It was running a bit rough so I figured Id take it to a trusted Toyota mechanic to see if it was the head gaskets. On the way their it started over heating pretty bad (for the first time, but no loss of coolant) I pulled over and made it there with many stops to cool down. At this point I am just assuming head gasket I checked the oil cap once there and it had a little white chocolate but not very much.

Very long story short I decided to do the head gasket job myself since I have the time and a garage. I start pulling the truck apart and I go to unplug my spark plugs and notice one of the boots is unplugged. Before I finish taking apart my engine I want to make sure that their is no way an unplug spark plug wire can simulate the engine over heat. I know for sure it could cause the loss of power. I still feel like it all adds up to head gaskets but I just wanted to get a little feedback.

MudHippy

What does unplugging a spark plug wire have to do with it?

Can you smell coolant in the exhaust?

mikaelm123

Sorry I hit enter too quickly. I really couldn't tell about smelling coolant in the exhaust. It could have smelled a little sweet I am not sure.

MudHippy

Oh I see. No. An unplugged spark plug wire won't cause an overheat. It might cause a change in the color/appearance of the exhaust though.

If I didn't smell coolant in the exhaust I'd be looking elsewhere for the problem. If you can see it, you can probably smell it. It's a very distinct smell.

Overheating is more of a cause for a blown head gasket, than it is the result of one.

Moisture on the underside of the oil fill cap is normal, to a certain extent.

I think you might be jumping to concusions thinking it's a head gasket.

What does your mechanic say/think?

mikaelm123

He just went right to "lets drop a new engine in their or sell it"

millball

Typical of a great many mechanics' thought process.

Mechanics want/need to get to the next money making job by quickly climbing over the top of your job.

His answer is the one that potentially maximises his profit, while not exposing him to any downside that there might be from any mistake, or lost time, from his failure to diagnose or repair any lesser real issue that your truck may actually have.

Precisely why I repair my own.