1995 850 Car having problems after heating up

zanemw · Post by **zanemw** » 12 Jul 2014, 16:41

When I drive on the highway my car tends to stay around 190 temp and when I'm driving around town for a while it starts heating up, gets to about 220 around that and when I park and come back the car starts doing weird stuff. Sputters and feels like it has no power and then turns off a couple times. After I restart it a few times and take it slow it gets back to normal and I'm able to drive around again, I noticed if I get it to cool down a bit before starting it I don't have the problem. What could cause that? Someone told me it was vapor lock, I looked that up and people says fuel injected systems can't get vapor lock.

Post by **erikv11** » 12 Jul 2014, 17:01

Out of curiosity, how are you determining those temperatures, scan tool of some kind?

Any codes?

If the ECT is bad then the temp readings will be off and the car can have difficulty starting, that would be my first thing to check. You can test the resistance of the ECT at fixed temperatures, search a little on this site for the values.

difflock54 · Post by **difflock54** » 12 Jul 2014, 17:18

Is the engine cooling fan coming on at the 220 degree point or thereabouts. One would expect it to.
My V40 runs at temp's about the same as you describe but ido not have any hot starting issues.

I am able to get specific temperature readings as I have an 'Ultra gauge' installed which is very useful overall but especially for engine temp's as Volvo temp' gauges are not super sensitive to gradual temp' increases or decreases. They jump to the RED from normal very fast with little warning.

zanemw · Post by **zanemw** » 13 Jul 2014, 20:06

The fan isn't coming on till about 230 degrees, I have mechanical sensor installed in the line the tells me the temperatures. Should the fan becoming on sooner? And what would cause it to not be turning on? I

difflock54 · Post by **difflock54** » 13 Jul 2014, 21:56

I am uncertain of the exact specified temp' that a fan should cut in but I understand its in the region of 220-230+ degrees.
Coolant additives of course raise the boiling temp' above the normal 212 degrees F for water
The main thing is that the fan is coming on to prevent overheating issues.

Post by **rspi** » 14 Jul 2014, 04:01

My fan and the fan on other white blocks that I have checked come on at 216° and go off at 204°.

You should replace your ECT ASAP.

zanemw · Post by **zanemw** » 14 Jul 2014, 06:31

While replacing the ect I noticed the thermostat had 2 small holes in the top. The person before must have drilled them into it would that cause problems?

Post by **abscate** » 14 Jul 2014, 07:28

Those are bleed holes to allow the system air to be pushed out when refilling, so they aren't the cause of your problems.

Post by **erikv11** » 14 Jul 2014, 07:29

Shouldn't cause the particular problem you describe, but I don't recommend it.

Here's why: I used to drill an extra (small) hole in all of my thermostats before install. It is a common practice to help prevent overheat on thermostat failure. I found that it made no difference in my non-turbo 850's but for the turbo ones, the engine ran too cool even in warm temperatures. I no longer do this on my Volvos.

zanemw · Post by **zanemw** » 16 Jul 2014, 15:47

Found the problem I let the car get hot and checked to see if the fan was coming on. The fan wasn't on I jiggled the wire on the fan a little and it turned the connection must be bad going to the relay.