Very strange cooling/slight overheating situation
08-08-2016, 05:40 PM
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Very strange cooling/slight overheating situation
I have a puzzler for anyone who wants to guess.
I have a 1988 3vze with 206,000 runs like a top.
I was concerned about a slight HG leak developing because it was stuttering on start up almost every time cold, sometimes hot, smelled pretty sweet, and i was losing coolant. It has never over heated though, and has a new water pump and now a new t stat. No visible leaks either before or after.
I figured because of the mileage and because I want to do an OM617 eventually rather than a HG project, I would try the Bar's HG 1 liquid fix just to see what happens. I have read a lot...I knew I was taking a risk.
The good news is that the rough starts are gone completely, as is the sweet smell, as is the coolant drop, so far after 600 miles. The heat also still works, as I was worried about this crap plugging things up.
The very strange thing that happens once in a while, not every time, after using the Bar's is that I will shut the engine off, go into a store for 10 minutes, turn it back on, and the heat gauge has risen after I shut the engine off. Not to the red, but a little above half. As soon as the engine idles for less than a minute it drops to normal, and doesn't over heat at all while I'm driving.
I have since drained the coolant system as best I could by just removing the t stat and lower rad hose figuring the Bars did its job if there were any small leaks and the excess in the coolant was creating some kind of pressure somewhere because of its fatness, and it was during this drain that I put in a new T stat while i was at it. I was able to put in almost 2 gallons of new antifreeze.
I don't know if I drained the whole system....I didn't remove the block plugs, but I drained almost 2 gallons as well. After the attempted drain and new t stat and burping it 2 times, I thought I had it because it had not happened but just later today it did it after it was sitting for about 10 minutes. Started it up, and the coolant gauge was a little above half...dropped to normal. Doesn't over heat while driving or idling, still blows hot hot air...very perplexed.
Any ideas? Could the sensor for the gauge be plugged or have some air trapped around it still because of the gunk I put in? Any remedies? I'm not terribly worried, but slightly. Mostly I am curious as to what would cause the temperature to rise, after the engine is off....seems like it must be isolated to the sensor.
Also, I doubt this is related but perhaps.
I am fairly sure I have a bad cat as the truck smells like farts when it is under load going up a hill. I have a new one on the way, though again with the engine off I'm not sure how that would effect the coolant temp.
This should be interesting.
I have a 1988 3vze with 206,000 runs like a top.
I was concerned about a slight HG leak developing because it was stuttering on start up almost every time cold, sometimes hot, smelled pretty sweet, and i was losing coolant. It has never over heated though, and has a new water pump and now a new t stat. No visible leaks either before or after.
I figured because of the mileage and because I want to do an OM617 eventually rather than a HG project, I would try the Bar's HG 1 liquid fix just to see what happens. I have read a lot...I knew I was taking a risk.
The good news is that the rough starts are gone completely, as is the sweet smell, as is the coolant drop, so far after 600 miles. The heat also still works, as I was worried about this crap plugging things up.
The very strange thing that happens once in a while, not every time, after using the Bar's is that I will shut the engine off, go into a store for 10 minutes, turn it back on, and the heat gauge has risen after I shut the engine off. Not to the red, but a little above half. As soon as the engine idles for less than a minute it drops to normal, and doesn't over heat at all while I'm driving.
I have since drained the coolant system as best I could by just removing the t stat and lower rad hose figuring the Bars did its job if there were any small leaks and the excess in the coolant was creating some kind of pressure somewhere because of its fatness, and it was during this drain that I put in a new T stat while i was at it. I was able to put in almost 2 gallons of new antifreeze.
I don't know if I drained the whole system....I didn't remove the block plugs, but I drained almost 2 gallons as well. After the attempted drain and new t stat and burping it 2 times, I thought I had it because it had not happened but just later today it did it after it was sitting for about 10 minutes. Started it up, and the coolant gauge was a little above half...dropped to normal. Doesn't over heat while driving or idling, still blows hot hot air...very perplexed.
Any ideas? Could the sensor for the gauge be plugged or have some air trapped around it still because of the gunk I put in? Any remedies? I'm not terribly worried, but slightly. Mostly I am curious as to what would cause the temperature to rise, after the engine is off....seems like it must be isolated to the sensor.
Also, I doubt this is related but perhaps.
I am fairly sure I have a bad cat as the truck smells like farts when it is under load going up a hill. I have a new one on the way, though again with the engine off I'm not sure how that would effect the coolant temp.
This should be interesting.
08-11-2016, 08:24 AM
#3
Could just be "heat soak." There are other parts of the engine that are hotter than the flowing coolant (hence, being cooled by the coolant) so once the flow stops the latent heat starts to dissipate and may rise to the sensor location.
I have a mechanical temp gauge and I see this happen often. I'm driving around and the temps are at 200. Stop for 5 minutes and the gauge is reading 220. Start it back up and in a few seconds it goes to 180.
No cause for concern. Just watch your coolant levels and check your oil filler cap for milkshake!
I have a mechanical temp gauge and I see this happen often. I'm driving around and the temps are at 200. Stop for 5 minutes and the gauge is reading 220. Start it back up and in a few seconds it goes to 180.
No cause for concern. Just watch your coolant levels and check your oil filler cap for milkshake!
08-11-2016, 08:42 AM
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Yea, I am going to guess its heat soak. Sure the engine isn't working anymore after its been turned off but all that heat is trapped in your engine bay, there's no airflow through the grill and the mechanical fan is not running to push chilled coolant though the engine. This seems only natural to me that it would have a slight temp increase, especially if its sitting in the sun. Just keep watching this, if it seems like its getting worse and worse, then I would say you might have a problem.
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