coolant loss???
 

I am loosing coolant. It started out slow but seems to be getting worse. I replaced the water pump, rollers, t-stat, and the head. I'm hoping it isn't the head, but there is no evidence of leaking external to the engine.

My MPG numbers were way down, and the idle was terrible. So I tested and found 2 intake leaks on the intake system. After running a couple tanks of gas through, there was no improvement in MPG, so I changed the O2 sensor. Immediatly it went from 22 to 26.5 MPG. The next tank was 26 MPG. The last one was 22 mpg for the same type of driving conditions.

I'm betting that I am loosing coolant into a cylinder when cooling down, then when it fires off, the exhaust is contaminating my O2 sensor.

Anybody have any other theories? Damn I hate to pull that head again. It is a major PITA.

Head Gasket ???

open the oil cap and see if there is any sign of a mayonaise, if so sure sign.

if no other obvious signs (ie antifreeze coloration) sounds like ti could be the head gasket

is a head gasket a big job? i can sorta smell what might be coolant and my mpg isn't good and my idle is a little rough. maybe i'm having the same problem.

Time for a leak down test?

//Magnus

I did my head. It wasn't that bad, but I also have a timing belt tensioning tool. So, I could do everything in the garage.

It took like a little over 2 hrs for me and the old man to tear it down. It took about that to get it all back together. No real big snags either. Everything came off easy.

I did everything by using the haynes manual, and it was pretty accurate.

I lost most of the coolant out of the tank on a 300 mile drive b/c the tank cap was 1/2 tun loose, DOH. that may not be your problem but it almost gave me one.

jason