Higher temp thermostat for wvo? - PeachParts Mercedes-Benz Forum

petecooke · #1 05-07-2012, 10:01 AM

I have a 1984 300d and I'm running 100% wvo with a 2 tank system. I have a FPHE before the IP.

My car runs very cool. Just about 60 on the temp gauge. I was thinking about replacing the thermostat with a stock or a higher temp thermostat. Does anyone know where I could get a higher temp thermostat? Brand/size/model?

I was also thinking that it's better on the motor life if the engine is running cooler but since I'm running wvo, I need the fuel hot. Any thoughts on this?

I was also thinking about not replacing the thermostat and adding injector line heaters. That way the engine runs cool but the fuel is hot. Would that be the ideal situation for any car running wvo?

Thx

pete

spark3542 · #2 05-08-2012, 12:45 PM

60 is too low. If it's truly 60, then your Tstat is stuck open. Stock should be around 80-90.

Cooler may be better for a gasser, but diesels run better hot.

scottmcphee · #3 05-09-2012, 02:23 PM

Quote:

Originally Posted by petecooke

I have a 1984 300d and I'm running 100% wvo with a 2 tank system. I have a FPHE before the IP.

My car runs very cool. Just about 60 on the temp gauge. I was thinking about replacing the thermostat with a stock or a higher temp thermostat. Does anyone know where I could get a higher temp thermostat? Brand/size/model?

I was also thinking that it's better on the motor life if the engine is running cooler but since I'm running wvo, I need the fuel hot. Any thoughts on this?

I was also thinking about not replacing the thermostat and adding injector line heaters. That way the engine runs cool but the fuel is hot. Would that be the ideal situation for any car running wvo?

Thx

pete

Add injector line heaters, they are a must. Regardless of how hot your coolant is heating fuel going into the IP, when fuel exits the IP and travels down the hard lines it will have dropped easily 20C degrees from what your interior gauge reads.

If your car is reading 60C you are probably getting around 40C at best at the injector while you're driving (wind rush over engine). Not hot enough for SVO/WVO. You can check this yourself by getting a small dial gauge metal probe style thermometer and lash the tip of it alongside an injector line near the injector, and insulate this with a wrap of cloth that is about 2 inches thick. This is the only true reading that matters. You'll be shocked!

If you can't afford or don't want to do heaters right away, just wrap the lines with insulation having some good R-value to it that can take engine heat without melting. Maybe it will look stupid but engine thanks you.

petecooke · #4 05-09-2012, 03:03 PM

Today my temp gauge got to about 70 but it never reached 80. I will replace the thermostat.

I am going to install line heaters also. I'd liked to get a thermostat that will turn the line heaters off if the temp gets over 250. I don't want a fire in my engine compartment.

Do you have a thermostat for your line heaters? If so, what type and where did you get it.

Thanks.

Pete

scottmcphee · #5 05-11-2012, 12:25 AM

Some vendors have snap thermostats that tuck under the heater wrap to cut out when a temp is reached.

uneasysunday · #6 05-19-2012, 02:17 AM

I added the highest thermostat I could find, worked great. I think its 195- or 205. Got it from Advanced auto parts. Just go to their website and type in your car and look at the specs on thermostats. Go with the highest you can get. I think the brand was Beck Arnley. I drive a 79 240d

sassparilla_kid · #7 05-19-2012, 02:45 AM

As long as the car is running at 80*C and you are heating the oil with the coolant then you should be fine. My car used to run really cool before I changed the thermostat and it still ran fine, and not it runs a little hot and I haven't noticed any difference

petecooke · #8 05-19-2012, 08:24 AM

Thanks for all the info. I ordered a new thermostat and it should be today.

pete

petecooke · #9 05-27-2012, 03:41 PM

I put the new thermostat in and my car is running about 90C.
The old thermostat did not have the gasket installed properly. The gasket was just placed inside the thermostat housing and then the thermostat was pressing against the gasket.
The thermostat was not inside the center grove of the gasket.

I'm surprised that it never leaked. I think this caused the thermostat to always remain open.

Also, I snapped the head off the top bolt when removing the housing. The other 2 bolts came out easily. After 2 hours of adding pb blaster, heat, vice grips and pliers, I just installed the new thermostat and tightened the 2 good bolts. No leaks but I'd like to get the broken bolt off in the near future.

Any ideas on how to remove it without pulling the other part of the housing off the block? I'd rather not have to remove it from the block and drill the bolt out.

Pete