'92 3300 Intake leak cause rough running?

[maxman]

'92 Grand Am 3300 V6 186,000 miles.

There appears to be a coolant leak from the intake manifold. If I use compressed air, and blow the coolant away, it seeps back into the area on top of the engine block at the manifold interface. I am quite sure that there is a coolant leak here. Is a failed intake manifold gasket common?

Will an intake manifold coolant leak cause the engine to run rough? It seems like it is not running on all six. Before I commit my time to fix the coolant leak, I would like to have the engine running smooth so that I can estimate to the owner what it will cost in parts. I don't want to just start throwing money at plug wires, plugs, etc.

Thanks in advance!

[xeroinfinity]

Plugs and wires are probly the cheapest place to start.

But yes coolant leaks can cause it to miss and run rough if it is leaking into one of the cylinders.

I would also say, from what you described, that your lower intake gasket is bad.
That leaking area is common with alot of engines.
And they can just blowout,
and that puts you in danger of overheating the engine, that's no good.

Though It could be a head gasket blown thats causing your rough running.
A cylinder compression test call help identify if it is bad.

Also is thier any coolant in you oil, or oil in your coolant?

[maxman]

No water in the oil. Not sure if oil in the water. Will find out when I drain the coolant. Thanks a bunch!

Was trying to avoid pulling the plugs because I have heard of horror stories about stripping out the threads or seizing in the aluminum block. I guess I will find out.

[xeroinfinity]

If you want to avoid stripping out the hole start the plugs by hand, then tighten.

Also use Anti-sieze on the threads of the new plugs.
This will make it easier to remove them in the future.