I had the car serviced a couple of weeks ago, the shop changed oil & filter, replaced rear rotors and pads and replaced the starter.Two days later I am driving to work and I glance down at the dash and see that temp. gauge that is normally always in the middle is climbing and then dropping back down and climbing again. It never got to the red zone but it freaked me out. When I got to work about 5 minutes later I popped the hood and I could tell it had been running hot. I tried to restart the engine and it would not turn over, I thought the engine was seized up! I later found out that this was the first no start of the replacement starter.

Even though I had replaced the thermostat about 2 years ago I decided to replace that first and that did not work, the lower rad. hose was cold and the upper very hot. After removing the new thermostat I was getting flow through the radiator. The water pump appears to be original but does not leak and has no play. With the thermostat removed the temp. gauge is on cold until I drive for a while then sometimes the gauge will start to move up about a third of its travel then back down again sometimes it stays on cold. The car is a 96 with 112000 miles.

I decided to replace the water pump and had to replace the defective starter. I would never know when the rebuilt NAPA starter would work or not. I would have to bang on the starter to get it to work and it was getting worse. My mechanic is a Bosch dealer and if I buy the starter through him I get a 2 year parts and labor warranty. So I managed to get the car started one last time and drove it to my mechanic ( I was going to have it towed) On the way there the temp gauge starts cycling up and down again but this time for additional fun the alternator (which has been acting up for a while) decides it has had enough and starts showing serious discharge. I managed to get it there that night and dropped off the keys in the box.

When I talked to the owner- mechanic the next day he told me there could be a possibility of a blown head gasket but he was going to replace the water pump first and then do a test for exhaust gases in the coolant. He will also replace my alternator with a good used one I have. I will find out in the next couple of days what is going on, the fact the the temp gauge cycles up and down fairly quickly has me worried though. I do not know if a water pump even if it was failing would have that cycling effect on engine temps.

 

Long shot but it's possible there is a common cause here, especially as you just replaced the starter.

The issue with the temp gauge fluctuating quickly can be caused by poor engine earth strap. It attaches at the starter motor so having been disturbed it may be loose.

Obviously a poor earth can also cause the starter not to turn and could also be a root cause for the alternator issue.


Worth checking before sinking lots of cash on parts and labour.

 

Well I have good news, the overheating problem was the water pump. The temp. gauge is now constantly just below the middle point. The Bosch remanufactured starter works every time and my spare used alternator has a much higher charging output, so everything is good, till the next time!