Marker

This is the place to get help with technical matters concerning your M151 jeep

Moderators: rickf, raymond, Mr. Recovery

Post Reply
rupert's
Master Sergeant
Master Sergeant
Posts: 337
Joined: March 29th, 2020, 7:10 am
Location: España

Marker

Unread post by rupert's » June 26th, 2022, 5:37 pm

Hi guys! I have a query to ask you about the temperature marker.

This is my temperature marker...
Marcador temperatura (1).jpg
It usually shows 180º but, when it's hot on the street, 90º or 95º the temperature rises if I demand performance from the engine.
With 90 or 95º on the street, if I go uphill on the road (in high gear) the temperature of the gauge rises to 200º, then I get scared and lift my foot to cool it down a bit. I don't know if I continued if the temperature would continue to rise.
If I go up the mountain with a lot of slope in first gear, the temperature of the engine also rises...
The question...
Should I be worried? Is it normal for the engine temperature to rise with heat? Is it possible that the pump is not working properly?

I don't know how big the thermostat is, I bought the engine used and it came with the thermostat on. I guess it will be 180º
A greeting and thanks for your help!
You do not have the required permissions to view the files attached to this post.
Last edited by rupert's on June 27th, 2022, 5:29 pm, edited 1 time in total.

User avatar
rickf
General
General
Posts: 19738
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: Marcadores

Unread post by rickf » June 26th, 2022, 7:52 pm

If it has a 180 thermostat then a reading on the gauge of 200 is not all that bad. You are running a 50/50 mix of antifreeze aren't you? Between that and the 12 lb. radiator cap you will have no issues overheating up to 230 degrees at least. Since you do not know what thermostat is in it it would be a good idea to buy yourself a new 180 thermostat and put it in so that way you know for sure you have a good thermostat. But what I would also do is buy some radiator and engine block flush and once you take out the old thermostat put the thermostat housing back on without the thermostat and run the flush through the system per the instructions. If you do get a lot of crap out of the engine and radiator I would go one step further while you have it apart and take the radiator out and turn it upside down and flush it out from the bottom, this will get most of the loose stuff that come is from the return line on top and flush it out the top. Then put it all back together with the new thermostat and new antifreeze and take it for a ride over the same course you had issues with and see if the readings are the same. Keep in mind that the gauges in these things are far from accurate and are basically just indicators to tell you if there is a major problem. Chances of the gauge saying it is 200 degrees and it actually being 200 degrees are slim.

And I always tell people to run a 180 thermostat even though the factory ran 160 because the 160 is far too cold. The engine is not up to optimum running temperature and also it does not evaporate out the condensation that naturally forms in the engine as it cools. I am sure you have already checked your fan belts to make sure they are tight.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

rupert's
Master Sergeant
Master Sergeant
Posts: 337
Joined: March 29th, 2020, 7:10 am
Location: España

Re: Marcadores

Unread post by rupert's » June 27th, 2022, 3:18 pm

Yes, mix 50/50 antifreeze, the radiator cap I do not know if it is 12 pounds, but the cap is new and I bought it on an m151 parts website.
So I am going to buy a new 180º thermostat and the radiator was cleaned at a radiator shop a year ago, I suppose it will be clean, what may have some garbage is the engine block, so I am going to look for the cleaner that you say and I will do the process.
https://www.autodoc.es/liqui-moly/78893 ... sMQAvD_BwE supongo que será esto.
Since I change the antifreeze it costs me nothing to do the cleaning before the change.
Is it supposed that after this the temperature will not rise?

User avatar
rickf
General
General
Posts: 19738
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: Marcadores

Unread post by rickf » June 27th, 2022, 3:49 pm

The temperature will always rise a little bit under a heavy load but it should not go over 200 degrees with a 180 thermostat. But, remember what I said about the accuracy of those gauges. You do not have one of the winter covers on the grill do you? I see them all the time even in the summer because people think "They look cool". Maybe, but even with it open all the way there is still a lot or restriction there. What you need to do to check the accuracy of the thermostat is to start it up cold and then with it set at a medium high idle with the hand throttle just watch the gauge as it rises until it opens and you see the gauge drop down a ways. It should go just a little bit above 180 or possibly just a bit below but close around 180 degrees. If it is higher like 190 then you can figure you gauge is off by 10 degrees and just figure that into your calculations when looking at it. 200 would actually be 190. But like I said 230 would not be out of the question although I would have pulled over by that point and let it idle. If it gets to the point of boiling over you will need to start looking for a blown head gasket. Either with a combustion gas tester or fill the radiator to the very top and let it idle with the cap off and watch for bubbles.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

rupert's
Master Sergeant
Master Sergeant
Posts: 337
Joined: March 29th, 2020, 7:10 am
Location: España

Re: Marcadores

Unread post by rupert's » June 27th, 2022, 5:27 pm

Understood Rickf! Thank you very much for your answer, as always, clear instructions.
I don't have a winter cover, this weekend I hope to have time to clean the circuit, put the thermostat on and check the temperature. All the best

User avatar
Lou
Staff Sergeant
Staff Sergeant
Posts: 155
Joined: February 5th, 2020, 10:54 am
Location: New Jersey

Re: Marker

Unread post by Lou » July 3rd, 2022, 6:39 pm

Our mutt with a 180 thermostat in the summer will read 180 in the woods. In summer running at 50 MPH it slowly climbs to 190. Have never seen it hit 200. Good Luck.
Take Care,
Louie
M151A2,
KA2PFL,
MVPA 27368
Image Image

rupert's
Master Sergeant
Master Sergeant
Posts: 337
Joined: March 29th, 2020, 7:10 am
Location: España

Re: Marker

Unread post by rupert's » July 3rd, 2022, 6:44 pm

Rikf! This weekend I have cleaned the water circuit, the cleaning product has come out black and also a little dirt but not much.
I have flushed the engine with clean water and refilled with antifreeze. I have a new thermostat to put, but I could not remove the one I had on, it seems to be very well glued and in the end I have left it on. I think it's an old thermostat, maybe someone knows what temperature it is and if they advise me to remove it or leave it.
All the best
You do not have the required permissions to view the files attached to this post.

User avatar
Lou
Staff Sergeant
Staff Sergeant
Posts: 155
Joined: February 5th, 2020, 10:54 am
Location: New Jersey

Re: Marker

Unread post by Lou » July 3rd, 2022, 7:12 pm

My opinion is remove that old thermostat, even if you have to destroy it to get it out. Install the new thermostat You purchased. A stuck or bad thermostat could damage your engine.

I have to admit, have never seen a thermostat that looked like that, would love to see the other side of it! :wink:
Last edited by Lou on July 3rd, 2022, 7:14 pm, edited 1 time in total.
Take Care,
Louie
M151A2,
KA2PFL,
MVPA 27368
Image Image

User avatar
rickf
General
General
Posts: 19738
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: Marker

Unread post by rickf » July 3rd, 2022, 7:13 pm

That appears to be an old original style and if it is it will be a 160 degree thermostat. So if you are getting upwards of 200 degrees with that one in then either the block is (was) clogged or the thermostat is bad. Personally if I had a new one I would bear=t that old one out of there. Take a screwdriver and get on the raised edge of it and smack it with a hammer across the hole and it will either come out or it will deform enough to get under it and pry it out. The thermostat is brass and the block is cast iron so you are not going to hurt the engine block as long as you do not hammer directly on the block. Once you get the old one out simply clean out the groove it sets down in and put your new one in with a new gasket and you are good to go.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

User avatar
rickf
General
General
Posts: 19738
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: Marker

Unread post by rickf » July 3rd, 2022, 7:14 pm

Lou, That is a flapper style and opens sideways. the pivot is in the middle.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

User avatar
Lou
Staff Sergeant
Staff Sergeant
Posts: 155
Joined: February 5th, 2020, 10:54 am
Location: New Jersey

Re: Marker

Unread post by Lou » July 3rd, 2022, 7:17 pm

rickf wrote:
July 3rd, 2022, 7:14 pm
Lou, That is a flapper style and opens sideways. the pivot is in the middle.
Learn something new every day, never saw one like that! :)
Take Care,
Louie
M151A2,
KA2PFL,
MVPA 27368
Image Image

rupert's
Master Sergeant
Master Sergeant
Posts: 337
Joined: March 29th, 2020, 7:10 am
Location: España

Re: Marker

Unread post by rupert's » July 4th, 2022, 4:40 pm

I'll do some tests and finish changing the thermostat when I have a while... That old thermostat doesn't give me much peace of mind :D :D

User avatar
rickf
General
General
Posts: 19738
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: Marker

Unread post by rickf » July 4th, 2022, 8:08 pm

Especially if the flush came out black. That is with a thermostat that was probably closed at the time and no real circulation was happening. This would be good as in nothing dirty from the engine went into the radiator but bad because the full flow of the water pump was not actually flushing the engine out as it would with no thermostat in. If you decide to flush it again check the condition of the coolant when you drain it and if it is fairly clean you can reuse whatever you can get out of the engine. You will not get all of it because some will be trapped in the block so when you refill you will still need to add some new coolant but if you can save most of the old coolant that can be a lot of money saved.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Post Reply