First of all, hello to all of you, My name is Tommy and I have a 99 Rodeo with the DOHC v6 engine. I am a brand newbie to this forum but am active on quite a few others - mostly Italian cars because I am a serious glutton for punishment....


Ok, a few weeks ago I noticed that the Rodeo is running hot and the next day I check the radiator and its almost a half gallon low. There are no apparent signs of leakage and there is no oil in the coolant or coolant in the oil and the engine runs fine so I did not suspect head gasket issues. Fast forward to this morning, the engine runs rough and stumbles a bit and the check engine light comes on. I run the codes and I come up with misfire on cylinder 4. After I pulled the coil pack I noticed that it was wet with coolant. I looked in the tube and could see a pool of coolant almost up to the ceramic part of the plug. I soaked up the water as best I could then pulled the plug. It looked normal with no oil or water on it. I then checked all the other plugs. 3,5,6 all have a similar condition as number 4 but not as bad.


I can see why there was a misfire because the water caused a short to ground on number 4. It runs great right now, but I suspect that the coolant will reappear in the tubes in short order. So how does coolant get in the spark plug tubes? Leaking head gaskets? If so you wouldthink that performance would have been way down, and it was not until just this morning and that was only because of the fouled coil pack lead.


Anyone have any ideas here... How hard is it to pull the valve covers? Looks like a MAJOR PITA on the drivers side.


Any input would be greatly appreciated.


Tommy


Edited by: TommyinAZ

Have your mechanic take a look, sounds like a head gasket issue.

It sounds like mine did when the head gasket was leaking. Prepare
yourself for the cost....around $400, as they have to take half the
engine off to get to it. Good luck

Get a compression tester for $30 bucks and test the compression yourself. You already know it''s leaking water. If compression is low, check oil. If oil is muddy green and thick brown, then your oil and coolant are not mixed up...usually a proponent of HG blown. Mine was a slow leak. It showed up in the oil first as car was running just fine.


I didn''t want to mess up the motor so I parked it right away and compression tested it. To make it short, I couldn''t pull the head, and am currently replacing the motor. ;) Good luck.