Vanning.com logo
Boxdin
Site Navigation


Advertisements
Recent Posts
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
1987 G20 Gypsy
by SDMickey - March 25th 2024 9:39 pm
Featured Links


Previous Thread
Next Thread
Print Thread
Rate Thread
New Thermostat high reading
#745052 February 07th 2019 8:15 pm
Joined: Dec 2011
Posts: 185
J
member
OP Offline
member
J
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?

[Linked Image]

Last edited by JDouglas; February 07th 2019 8:42 pm. Reason: Photo failed to load
Re: New Thermostat high reading
JDouglas #745055 February 07th 2019 9:10 pm
Joined: Sep 2005
Posts: 9,855
Likes: 234
carpal tunnel
Offline
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
JDouglas #745061 February 08th 2019 9:37 am
Joined: Feb 2019
Posts: 29
M
newbie
Offline
newbie
M
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
JDouglas #745062 February 08th 2019 10:03 am
Joined: Sep 2013
Posts: 1,015
Likes: 19
old hand
Offline
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.


[Linked Image]
Re: New Thermostat high reading
JDouglas #745064 February 08th 2019 12:31 pm
Joined: Dec 2001
Posts: 3,455
Likes: 23
O
pooh-bah
Offline
pooh-bah
O
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
JDouglas #745065 February 08th 2019 12:41 pm
Joined: Nov 2013
Posts: 2,286
Likes: 153
W
veteran
Offline
veteran
W
Joined: Nov 2013
Posts: 2,286
Likes: 153
Hey JD,

Marcela, JO, Jason, and Catfish right on info input all good! "Tiny Bubbles," cheers 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... grin

Re: New Thermostat high reading
JDouglas #745076 February 08th 2019 5:57 pm
Joined: Dec 2011
Posts: 185
J
member
OP Offline
member
J
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
JDouglas #745077 February 08th 2019 7:02 pm
Joined: Feb 2019
Posts: 29
M
newbie
Offline
newbie
M
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
JDouglas #745177 February 11th 2019 5:52 pm
Joined: Dec 2011
Posts: 185
J
member
OP Offline
member
J
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.


Moderated by  Astro 

Link Copied to Clipboard
Donate


Upcoming Events
discovery
Who's Online Now
1 members (Meanmachine), 21 guests, and 2 robots.
Key: Admin, Global Mod, Mod
Newest Members
TheDrunkenGunsmith, Jac, LOVclassics, ZenMuffin, Milkman530
12724 Registered Users
Top Posters (30 Days)
SDMickey 125
CatFish 25
frscke1 25
Wedgy 21
Forum Statistics
Forums68
Topics35,746
Posts537,916
Members12,725
Most Online177
May 8th, 2013

Powered by UBB.threads™ PHP Forum Software 7.7.4