Author Topic: Is 220 degrees too hot?  (Read 393 times)

April 05, 2019, 01:48:10 pm


  • Junior

  • Offline
  • **

  • 180
    • View Profile
Is 220 degrees too hot?
« on: April 05, 2019, 01:48:10 pm »
 What is the optimum coolant temp for a 1.9TD?
 180 degrees to what?

 On my samurai conversion, I was getting 215-220 deg after climbing a long, off road 300m climb in second gear. Temps hit 220 at the top of the hill.
 Yep, both fans were running, and the temps did come back down to 190 after a few minutes of idling.

 Assuming my T stat is the common 87 deg. I now have an 82 deg T stat to swap in.

 What is the temp that you don't want to hit? ......risk of overheating, warping the head, etc..

Reply #1April 05, 2019, 08:57:05 pm


  • Veteran

  • Offline
  • ***

  • 3693
  • Personal Text
    Restoring a Caddy and cleaning the Rabbit for sale
    • View Profile
Re: Is 220 degrees too hot?
« Reply #1 on: April 05, 2019, 08:57:05 pm »
I would say it is more of a function of how hot and how long.  The cooler on the oil filter gets its water off the bottom of the radiator so it should be less than what ever you have for a thermostat but not by much.  That of course only applies if the radiator is working as designed.  And that you don't have other items stacked in front of it.  Like aftermarket oil cooler or intercooler. 

If you spike temps occasionally to the 210 mark I doubt you will do damage if you have proper antifreeze coolant to keep boil over from happening.  If you are running simple water then you are risking steam out the coolant reservoir and then less fluid in the future.  Bad choice in my mind to run water unless it is an emergency fix.  With the price of a gallon of unmixed antifreeze at about 10 bucks you can give up a beer and a coffee for the day and save your engine.

My gauges, Mechanical, tell me I run around 90 C or 185 depending on the vehicle I am driving.  I don't have extreme heat here on the Pacific ocean to contend with but rather I fight a cool engine most of the time.  So I run a hotter thermostat rather than a cooler one.
Turbo and Exhaust finally on, Time for tuning!

Reply #2April 06, 2019, 12:25:46 pm


  • Junior

  • Offline
  • **

  • 180
    • View Profile
Re: Is 220 degrees too hot?
« Reply #2 on: April 06, 2019, 12:25:46 pm »
 As a comparison, in my 95 golf, DD, 1.9TD, I run about 85-90C on a warm day, normal commute. A littler cooler on a cold day tho, say.....if it's 5 deg C outside. oem vw rad and vw pink coolant.

 My question is regarding my samurai with aaz. It's got the Acme diesel conversion rad, and vw pink ?G12? coolant. All of the cooling components are brand new, except the T stat.

 Been taking it off road and the temps sure climb as the elevation and long grind up the mountain in second gear continue. On the pavement commute, it sits around 85-90C +/- a little depending on the hills. If it climbs past 90C going up a hill, the temp comes back down quickly when I get up onto the flat, or the downside of the hill.
 I do have the fuel turned up, 1.6TB boost pin, and max boost of 15 psi for the Ko3. Water / meth injection also.
 So yeah, the zuk is heavier than my golf, runs more rpms vs kmh than the golf, and of course the air flow through the rad is not great at only 20 mph [ second gear ].

 I'll consider 220 deg the time to pull over and let the engine cool......until I learn otherwise. Better safe than sorry.

 BTW, 90C = 194F
          85C = 185F
           104C = 219.2F         
« Last Edit: April 06, 2019, 12:28:16 pm by Spokerider »

Reply #3May 07, 2019, 08:26:06 am


  • Junior

  • Offline
  • **

  • 50
    • View Profile
Is 220 degrees too hot
« Reply #3 on: May 07, 2019, 08:26:06 am »
In my case the oil temps never go above 220F until its above 90F. Then it was 230F and when it was 100F it was hitting 240F until I hit 250F at 110F climbing a long steep hill . I had 40psi of oil  pressure so I was fine driving at 55mph and didnt burn any oil for the trip.
Have the rubber gasket installed, all the cooling tin, really no oil leaks and timing was checked before the trip at 27 degrees at 3500rpms.
I am running a stock VW used 72 muffler until I repair the S&S extractor I broke.

The boiling gas in the tank seems to be the big problem as when I was at a third of a tank I started losing power and ran hotter. Then I would get vapor lock and the engine would die. My guess is it was then running leaner with less power due to the heat control valves dumping that hot air right below the gas tank. I also think the case also gets heat soaked so the oil temps rise too.

Once I reached Wenatchee next to the river and the temps outside were cooling down to 95F I had no problems. Back up to 60-65 mph and cruised home via Highway 2 which is beautiful compared to I90, Colin should take this route and enjoy a night in Leavenworth.
So I located a set of 79 control valves and the tubes to install and the test will be to see if this changes the gas tank issue. After that Ill install the S&S header to see if that makes a difference as before when the header was on I never had this issue traveling thru 100F heat.

So Randy, what is the foam you are talking about?


Canada Catalys