Pulsating idle - belated thanks

[alamostation]

When I bought my car two years ago, I had a pulsating idle and asked for advise here. It turned out to be a bad o-ring on the idle screw. Many people suggested air in the cooling system.

This week the problem came up again. I opened the hood to check the coolant level and noticed the coolant return line was broken off the reservoir cap and there was electrical tape on it. The reservoir was below low. Turned out that the "technician" at the local shop offering the 17.95 synthetic blend oil change broke it while doing the oil change.

Thanks to the helpful people here I knew right where to start my search.

For other people's future reference, the o-ring problem is continual, the coolant problem goes away after the engine warms up.

Another tip: park the car on a steep downhill when you add coolant through the filler cap in front of the reservoir and you wont have to worry about bleeding the system.