Skip the auto shop - Our mechanics make house calls

Q: When installing a new water pump and thermostat on my 1989 Pontiac grand Prix should I use gasket sealer or silicone grease

asked by on

I'm not sure if I should use gasket sealer or silicone grease when I've replaced my thermostat and water pump on my 1989 Pontiac grand Prix and don't know if that might be why it looks like coolant is still leaking from the brand new water pump I just installed
My car has a manual transmission.

In your application, the new thermostat comes with a new rubber seal which is the entire gasketing solution for the thermostat housing. Nothing should be added as that may interfere with the seal. The water pump uses a paper/fiber gasket. So long as the mating surfaces on the pump and engine are perfectly smooth, have no pitting, are clean and down to bright aluminum, and are not warped, there is no need to coat the paper gasket with RTV sealant. If there are defects in the metal surfaces, sealant will help but if no defects are present the sealant is superfluous; the gasket makes the seal. A leak proof seal with a paper gasket in this application requires that a torque wrench be used to tighten the pump bolts in sequence to 89 inch pounds (7.4 ft. lbs). YourMechanic can dispatch a certified mechanic to troubleshoot this if there is a leak. The service to request would be pump installation. Please let us know if you have further concerns or questions.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  • Home
  • Questions
  • When installing a new water pump and thermostat on my 1989 Pontiac grand Prix should I use gasket sealer or silicone grease

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: front passenger wheel locked up.

Hey there, thanks for writing in about your 1989 Chevrolet K1500. You say it may be the axle so I guessed you have a 4x4 vehicle. You will need to isolate the axle to see if the wheel bearing in...

Q: The temperature gauge goes above middle too hot

If the gauge is moving into "hot" territory, then the car is overheating. You will not necessarily leak water during an overheat. Overheating can be the result of a couple of different failures. I will start with the easiest to...

Q: what other issues can occur if a misfire troubleshooting problem is not fixed soon enough?

Unfortunately, it is possible to damage the catalytic converter, that is cause a blockage, if the engine misfires "too much" and/or for a prolonged period. It is not yet known whether your converter is damaged, but I will get to...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...