Blown Head Gasket? - Toyota Nation Forum : Toyota Car and Truck Forums

Shinigami · 02-01-2009, 08:28 PM

Hi all, wondering if anybody has had this experience...

My car has been running rough, basically dropping down to 500 rpm when idling, then going right back up. Car was hesitating at low rpm and then "kicking in" once I get up around 2500.

I decided I'd try putting in the new spark plugs I had laying around to see if it would help. Cylinders 3&4 came out pretty clean, but that's when things went downhill. Both #1 and 2 were coated in coolant when I pulled them out! at least I can't think of any other bright green fluids it could be.

I'm wondering if this could possibly be anything that doesn't involve getting a new(er) engine? Could it be something as simple as a head gasket?

verlaryder · 02-01-2009, 11:17 PM

Coolant and/or low compression in two adjacent cylinders are classic symptoms of a blown head gasket.

***toyomoho*** · 02-02-2009, 08:43 AM

Might be just the head gasket but should have the head inspected for cracks.

Shinigami · 02-02-2009, 07:49 PM

Ok, I'm gonna check it out this week if I have time. The car has over 190,000 km on it. If I'm taking this thing apart should I be looking for worn parts of any kind? I'm not sure if people generally replace valves or anything else once the mileage is up there. It seems like a good opportunity to replace anything that's lowering performance or that's going to break later.

Brian · 02-06-2009, 02:57 AM

IMO, diagnose it properly first. If the conclusion is head gasket, then just slap a new Toyota head gasket in there and call it a day. Change your thermostat, rad cap, coolant, and engine oil while you're there.

Whatever you do, resist the temptation to install a TRD or other metal head gasket.

Shinigami · 02-07-2009, 05:15 AM

Ok, took the car to the AE86 wizard today. He narrowed it down to coolant seeping out between the head and block near the front of the engine. He got a huge wrench with the big hex head and wrenched down that front bolt (I think there are three)

I'm back to firing on all cylinders and no rough idling anymore. Changed the plugs which were old anyway and headed to the mountains and had an awesome day.

Remaining problem is that I can't get a reading on my temp gauge. Get a jump in the needle when starting the car, but it never shows any temp.

Also, not sure if my thermostat is messed up, but he said to unplug my cold start injector and see if that helped fuel consumption...

Thank you for all of the tips, and I'm sure I'll be back with more questions as I get this car back into good shape.

Brian · 02-07-2009, 05:33 PM

Quote:

Originally Posted by Shinigami

Remaining problem is that I can't get a reading on my temp gauge. Get a jump in the needle when starting the car, but it never shows any temp.

Also, not sure if my thermostat is messed up

How is your heat? Little or no heat is often caused by a failed thermostat.

The temperature gauge sender could be buggered up due to bad grounding of the upper water neck. Try unplugging the sender (single wire) and grounding it directly to see if the gauge sweeps to HOT. If it does, add a ground jumper to the upper waterneck.

Shinigami · 02-08-2009, 08:27 AM

Wow, grounding it should show hot? I'll give that a try tomorrow. ...Upper water neck?

As for heat it SEEMED like we were getting hot because the heater was kicking out some good heat and you could see heat coming off of the engine. Of course these are two very subjective ways to tell how hot the engine is.

Brian · 02-09-2009, 11:32 PM

If your heater is working well, then your thermostat is probably okay. Fix the gauge issue first.