Thank you for being a valued part of the CNET community. As of December 1, 2020, the forums are in read-only format. In early 2021, CNET Forums will no longer be available. We are grateful for the participation and advice you have provided to one another over the years.

Thanks,

CNET Support

General discussion

Pontiac g6 oil leak repair advice

Jun 27, 2017 11:55AM PDT

Hi,

I have a 2007 Pontiac G6 Convertible 3.9L engine, 47K miles. I have been doing regular oil changes at the dealership.

It started leaking oil recently.
After the diagnostic, dealership found oil leaking from
-Front crank seal
-Lower intake gaskets
-Upper intake gaskets
-Coolant crossover pipe
-Sealant
-Thermostat with gasket
Repair quote: $1950

I took it to a local mechanic thinking it might be cheaper, but he diagnosed it as
the problem with your car is:
rear main seal leaking
oil pan leaking
rear head gasket leaking
i have to remove the engine outside the car
remove both cylinders head and send them to machine shop to re service flat head , we will put new bolts and new head gasket
parts and labor 2000-2200

I am down $170 dealer diagnostic and $140 mechanic diagnostic and getting very different diagnosis.

KBB says the car is worth 5-6K for private party sale and 4K for trade-in.

Any advice? Should I go to a third mechanic? Is it worth spending so much on repairs when the car's value isn't much?

Is it better off selling this one? I'm OK buying a new one but would like to get the most value out of my dollar.

Discussion is locked

- Collapse -
Did you buy this car new?
Jun 27, 2017 12:18PM PDT

If you bought it used, might be worth a CarFax on it's title and see if you can trace it back to a flood state it was moved out of. However the damage you describe sounds like "crankcase explosion" may have caused it. That's when Pollution Control Valve or System isn't getting all the fumes/vapors from the crankcase and a bit of fire passing a piston causes an explosion in the crankcase.

I'd trade it in for a different GM product, since they probably will not even check it, just give you book credit on it, and I suspect they may be to blame for it's condition anyway.

- Collapse -
Actually the results are the same.
Jun 27, 2017 12:24PM PDT

You have leaks and for the shop to nail it they have to tear it down, replace what they suspect and then see if it still leaks.

In either shop you want to ask "Is this going to fix it?" and "If it doesn't am I going to have to pay more?"

- Collapse -
Multiple oil leaks?
Jun 29, 2017 1:54PM PDT

Hi; This whole thing sounds a little fishy, however, anything is possible. If you were my customer, I'd advise you to have the whole engine (top and bottom) steam cleaned. Then, there is a fluorescent dye that can be added to the oil, run for a while, then check for leaks with a black light. Remember, when a leak happens, gravity takes over. While you may have a leak up high, it will appear that it's all over the place, down lower. JMHO.
Loren