Good day by lukester - March 28th 2024 12:26 pm
| Crazy mods by MufflerMan Mike - March 28th 2024 9:38 am
| | Lew Greger by MufflerMan Mike - March 27th 2024 5:15 pm
| | | New Thermostat high reading | Joined: Dec 2011 Posts: 185 member | OP member Joined: Dec 2011 Posts: 185 | I've replaced the thermostat on my van along with a new seal, new upper and lower radiator hose and fresh 50/50 coolant. Drove it today and noticed the engine temperature gauge was reading very high. I mean getting near the 260 mark. I have no leaks anywhere and the coolant level is fine. I wondering if the coolant sensor has failed?
Last edited by JDouglas; February 07th 2019 8:42 pm. Reason: Photo failed to load
| | | Re: New Thermostat high reading | Joined: Sep 2005 Posts: 9,855 Likes: 234 carpal tunnel | carpal tunnel Joined: Sep 2005 Posts: 9,855 Likes: 234 | That's scary!! Did you get all the air out? I have had to remove the heater hose connection at the rear of the intake manifold (while refilling) to get that last pesky air pocket out. How about the rear heat and hoses? Some of the high mounted systems could trap air. If it was really that warm your clutch fan should have been engaged and raising a fuss/very loud. IIRC the gauge sensor and the computer use separate sensors and the gauge sensor is in the left side head. But don't trust me on that.......
Last edited by CatFish; February 07th 2019 9:13 pm.
| | | Re: New Thermostat high reading | Joined: Feb 2019 Posts: 29 newbie | newbie Joined: Feb 2019 Posts: 29 | Check that your radiator core tubes haven't ballooned, or you can still see through the radiator.
With air in the system you can see the gauge fluctuate quite a bit as air then water hit the gauge.
If your system lost a lot of coolant, then some goes through the system and hits a cylinder wall the resulting steam and expansion can rush through the system and balloon the radiator tubes. No air flow no cooling. (i've experienced this one)
After that check your fan belt and fan and make sure no air.
Also might do a pressure test on the system if you inadvertently ran it hot prior to the replacement and caused other issues.
Or you put the thermostat in facing the wrong direction.
Last edited by Marcela; February 08th 2019 10:02 am.
| | | Re: New Thermostat high reading | Joined: Sep 2013 Posts: 1,015 Likes: 19 old hand | old hand Joined: Sep 2013 Posts: 1,015 Likes: 19 | The new thermostat could be defective as well. If that is the only thing you changed and the overheating started immediately it points to the thermostat, or there is still an air bubble trapped somewhere. | | | Re: New Thermostat high reading | Joined: Dec 2001 Posts: 3,455 Likes: 23 pooh-bah | pooh-bah Joined: Dec 2001 Posts: 3,455 Likes: 23 | Also what temp thermostat did you install? Because I run my van only in summer I run a low temp version. Air trap has happened to me in the past.
1973 Dodge Shorty B-100 1995 Chevy G20 Gladiator
Life should not be a journey to the grave with the intention of arriving safely in a well preserve body, but rather to skid in broadside in a cloud of smoke, thoroughly used up, totally worn out, and proclaiming
"Wow What a Ride"
Johnny O "O Vanners" of Connecticut! Since 1982
| | | Re: New Thermostat high reading | Joined: Nov 2013 Posts: 2,286 Likes: 153 veteran | veteran Joined: Nov 2013 Posts: 2,286 Likes: 153 | Hey JD, Marcela, JO, Jason, and Catfish right on info input all good! "Tiny Bubbles," Sing it!! As an aside, I'd add look for bubbles in coolant flow, cap off, engine warm. A blown head gasket may pressurize the cooling system as well. This will force the coolant out of the cooling system. Absent a pressure test, A blown head gasket may be indicated by the presence of "Tiny Bubbles" in the coolant flow. Seen it, but IDTS in this case tho. My money's on trapped air. Those Tees that come in the Prestone FlushnFill kits are pretty handy for bleeding air out from the cooling system. Just install that puppy in an uppermost part of the heater hose, Presto! ne... | | | Re: New Thermostat high reading | Joined: Dec 2011 Posts: 185 member | OP member Joined: Dec 2011 Posts: 185 | Update: Drove 50 miles today and the reading was normal. Sat for about 1.5 hrs and drove back home the 50 miles and the reading was 260 for 30 miles then went to halfway mark the rest of the way home. I watched and listened for trouble signs and the only thing I saw was the needle doing a dance a few times. going back and forth from 125 - 200. This makes me think the problem is electrical. Again, there are no leaks anywhere on the engine or under the engine. the exhaust is normal/clear. I added enough coolant to top off the radiator before i left. | | | Re: New Thermostat high reading | Joined: Feb 2019 Posts: 29 newbie | newbie Joined: Feb 2019 Posts: 29 | I'll bet you're happy you don't have to pull that thermostat again:) | | | Re: New Thermostat high reading | Joined: Dec 2011 Posts: 185 member | OP member Joined: Dec 2011 Posts: 185 | I ran the engine with the heat on and radiator cap off for a good 20 minutes and I think i've got all the air out of the system. The temp gauge stayed normal (around the first mark). thanks for the tip on the trapped air. | | |
1 members (Meanmachine),
21
guests, and
2
robots. | Key: Admin,
Global Mod,
Mod | | Forums68 Topics35,746 Posts537,916 Members12,725 | Most Online177 May 8th, 2013 | | | |