"sniffer" says bad head gasket - believe it?

[iamburanto]

My 95 V6 3.0 4wd (which was made just after the head gasket recall timeframe) has started running hot.

It has 250K miles.

When I start and run it, the temp gauge just keeps climbing until I turn the car off and leave it to cool down and walk home.

I have not let it get all the way into red.

Since I have no milky oil and it does not blow any smoke, I figured the water pump was shot or maybe, if lucky, a thermostat was malfunctioning.

I took it to Toyota and they said that their fancy "sniffer" tool which tests for exhaust gas in the cooling system indicated a blown head gasket and $3000 fix.

If the gasket has failed, I will likely do the work myself ; challenging but one of those things I need to do myself.

I beg for advice on further testing.

Should I just believe the sniffer and bring the truck home to start pulling it apart or should I ask for a compression test or some other test.

Thanks for any help or advice!

 

[rustyrazor]

I'd get a second opinion.

Try changing the thermostat.

 

[Daemon]

If there were a headgasket leak you shouldn't need a fancy sniffer to detect it.

I vote thermostat. It's a little fiddly but not too hard to replace yourself once you figure out how to grab all the various hose clamps with pliers to loosen them. I used a clean container and drained the radiator and hoses between radiator and thermostat into it, so I could reuse the coolant (I'd already flushed it recently). Once everything is drained and the hoses are off, pull the thermostat housing off, scrape off any gasket goo, replace thermostat, clean the area with acetone and make sure it's dry. Apply new form-a-gasket, and re-install thermostat housing (don't overtorque or it'll squirt out all the form-a-gasket).
Let cure for a while. Re-attach hoses. Refill radiator, start engine with cap off, and then keep topping it off until it won't take any more. Should be good to go. Took me about an hour.

ian

 

[Andrea_Italy]

I'm having the same issue with my 2lt 4R. My mechanic used the sniffer (something like a small pump which sucks liquid from the radiator to check if there's any tracks of CO2 in the refrigerating liquiq) to see if the headgasket was broken.
In my case the sniffer failed :naughty: and the most probable issue is the radiator which has to be cleaned (internally).
Something else you can check is the radiator, first verify that the front side is cleaned (no mud) and then check if the liquid can flow inside it. The easiest way to check this last one is, once the temperature is hot, try to touch the front side of the radiator, and see if it is hot on all of his surface, if it isn't than you could have the same issue I have (liquid not flowing correclty in the radiator).

I'll update you once my mechanic finished all the tests (hopefully soon)

bye

 

[fd59]

I agree with Andrea_Italy. Probabbly the radiator. I would replace the thermostat and clean, flush, and flo-test the radiator. If that doesn't work then repalce the radiator. Considering the age and mileage I would repalce the radiator even if I had to repalce head gaskets.

Another item I would check would be the fan clutch.