thermostat question?

My local mechanic told me to get a new thermostat and gasket, most likley from an isuzu dealer. They told me that thermostat would be $28 & when I asked about a gasket, he at first hesitated then he said another $5.00.. That hesitation seemed kinda strange to me, so I went to Pep Boys & bought a Stant thermostat for only $19.00, & they said that the gasket was included.Is this possible & if so , is the gasket the black ruberized or plastic ring around the back end?....Reason for this is that I have a minor antifreeze leak which only leaks at different times.My mechanic says it may me a back up in the system because only certain hoses where hot while another was cool, so he said that a thermostat and gasket would do the trick. So before I install it I would like to know if he is in the right direction, Thx Bruce

NO! Stock thermostat is very different than I have seen (I would not expect it to be cheap or easily available) and the worst part is the ENTIRE intake manifold has to be removed to replace it. Has yours failed? Coolant leaking under the intake manifold is more often than not,(especially when it is intermittant) the water manifold's o-rings and those CAN be replaced without removing the intake. Do a search for manifold and you should find Ron's same issue - I have replaced my orings twice on that part.

Tone, The theromstat I picked up from Pep Boys looks almost identical to the one you posted, only difference is that the bottom of your picture seems to be a bit more of an angle. It appears to be at about a 55 degree angle,whereas mine is more at a 45 degree angle. Maybe its the way the pic was shoht at that made it look different. Everything else seems to look exact! Furthermore , I went and read the posts on the manifold as you suggested, yet none seemed the same as my problem....Is it possible that the thermostat is causing the minor drip at times ,due to a backup of antifreese? Remember ,some hoses wont get hot to the touch while another will. I hope Im making sense so that you will understand....thx, Bruce

Typically the manifold oring will leak when you turn the vehicle on or off, squirting fluid out under the manifold. If you look where the pipe comes out of the water manifold with a flashlight, I will bet you see a little (or big) squirt of fluid when you stop or start the engine. It is very unlikely that the thermostat is leaking - it will be a first I’ve heard of one leaking in over 5 yrs of these boards.

How long are you running the engine before you feel the hoses? In the cold it will take more time before the thermostat opens. If after 10-20 minutes or a long drive that the heater does not work well or hoses are not hot, then thermostat has failed in the closed position which is rare since they are now designed to fail in the open position. And even if the thermostat fails, that would not cause a leak. But if the gasket is bad, then replacing the thermo at that time is smart. How much is he going to charge to pull the manifold?

he said it would be about a 2hr job. Labor charges are about $70. per hr. What should I tell him to do, for he is very honest w/me for all the years I know him.?

I felt the hoses after about 20 minutes, yet I still get heat

And remember that its an erratic leak, only drips a little, and not all the time. Most of the time there is no drip for days