Roush Engine Experts.

[jhv48]

I read all the threads I could find including his.

My situation is a little different. All items are new SPF. For the past month, the engine temps have fluctuated a lot during normal driving. In town, 75 degrees out, stop and go temps would be 110 oil, 110 water. Get on the freeway, same day and the oil and water temps would back way down to 65-70 degrees.

The last two days, the oil temp would climb to 110 in about ten miles and the water to 120. Fan on, freeway driving had no effect on the water temp, but oil would back down to 105. Pulled into driveway and shut it off with the fan running and the temp spiked immediately and it puked all over the floor. Could hear the boiling coolant in the tank. Hoses were hot, radiator was hot, engine was hot. No sign of oil in coolant and no sign of coolant coming out of exhaust pipes.

Just took it back to the installer for diagnosis. Will let you know what he finds.

Would an intake manifold gasket leak cause these symptoms? How about if they forgot to install a thermostat? Leaking head gasket?

[patrickt]

Usually when you see "monster variations" you think air-bubble. Replacing the thermostat with one you've tested on the stove and burping the system (when you can't spot something obvious) is usually the first step.

[jhv48]

Problem solved.

Thermostat was sticking and finally stuck closed. DanMar fixed it.

Just drove it in 90 degree heat and stop and go traffic. Temp never got more than 100 degrees. All systems working fine again.

Now to focus on that front wheel vibration and then the side pipes.