No heat, overheating and coolant full??

[Francis K]

Hello all, could use a little help diagnosing this issue. For a few days the heat was barely working or taking a really long time to warm up and then one night on the highway my ultragauge beeped with a high temp warning, looked down and saw the same on the cluster. Slowed down and it went down, pulled off, bought some coolant, filled it up with the whole bottle and the rest of the way home the heat worked fine and it wasn't overheating. The next day the heat was't working right again and the day after that it was overheating again. Filled the coolant again, barely got it all in there this time and a couple days later same problem all over again.

Anyone have any ideas??

Thanks in advance!

 

[Francis K]

Oh by the way, it's been ass balls cold all the while!!

 

[94SRUNNER]

Sounds like there is either a leak in the coolant system or possibly an HG issue

More info on the rig helps as well. Maintenance history?

 

[scrowley]

Check your thermostat. Bet its stuck closed.

 

[94SRUNNER]

When you say you filled it up with the whole bottle, did you mean you poured the whole gallon container into the coolant system? Where did you add the coolant, The reservoir or into the radiator?

 

[Francis K]

Sorry guys, 97 LX with 160k. Babied it's whole life, maintained very well but never needed to do the HG.

Both in the radiator, the first bottle it took like it was empty and the second it was smoking when I opened the cap and barely got it all in.

Thanks guys, hope it's not the HG I always felt like I took such good care of her I may get lucky and avoid it, half knew it was wishful thinking.

 

[94SRUNNER]

Have you checked it over for leaks once it's warmed up? That seems like an awful lot of coolant to be adding...twice.

Was the engine hot when you took the radiator cap off?

 

[Qball]

Since it's really cold have you check for cracks in radiator or the freeze plugs? Maybe some parts got frozen.

 

[Howard705]

the coolant is going somewhere. Look. The heater doesn't work when coolant is low-there's no hot coolant in the heater core to heat it up.

 

[ThatMan]

I've had the same issue before. It had air pockets in the system. Check the radiator again and refill as needed. Repeat as necessary.

 

[LS1FJ40]

Sounds like a leak to me. That's a lot of coolant to be adding...

Just had a similar issue. Fairly simple to find the leak once you start the truck up which pressurizes the system. I had a small leak on the lower inlet hose to the radiator. It cost $12 and 15 minutes to replace. Fixed it yesterday. No more leaks.

 

[jakesiar]

Hello all, could use a little help diagnosing this issue. For a few days the heat was barely working or taking a really long time to warm up and then one night on the highway my ultragauge beeped with a high temp warning, looked down and saw the same on the cluster. Slowed down and it went down, pulled off, bought some coolant, filled it up with the whole bottle and the rest of the way home the heat worked fine and it wasn't overheating. The next day the heat was't working right again and the day after that it was overheating again. Filled the coolant again, barely got it all in there this time and a couple days later same problem all over again.

Anyone have any ideas??

Thanks in advance!

Have you checked your oil to visually see the color? I think someone also mentioned that your t-stat may be stuck (this could be it…) but sounds like you are losing coolant somewhere. No obvious leaks around the engine or under the vehicle?

 

[Toyotaoh]

Also, go to autozone and get a coolant fluid checker to find out how low a temperature you are protected. If you are not using the correct ratio of coolant to water, the coolant in your system will gell up and cause a no heat and overheat situation.

 

[Francis K]

Thanks for the tips everyone I put all of them to use!

I spent most of yesterday looking for a leak and couldn't find one, I was pretty much resigned to it being the head gasket. I had it in my warehouse overnight and saw there was coolant on the floor this morning, lo and behold there is a set of small pipes at about center of the truck close to the running boards leaking some coolant, I'm assuming they have something to do with the rear heat?? Well long story short the black pig is okay and she'll be back to striking fear into fellow motorists soon!

 

[94SRUNNER]

Glad to hear you found the leak. Those are a fairly common source of leaks. Lots of threads going through repairs and alternate solutions.

 

[Francis K]

Thanks 94S, what would I search for exactly to find those threads and info? I need to order the part but don't know what I should be asking for exactly, I'm assuming it's a dealer part.

 

[94SRUNNER]

I would search "rear heater", that should give you several threads. As for which part, you need to determine exactly where it's leaking from. Then you'll be able to narrow down exactly which part you need.

 

[EPIC Cruisers]

I'm having a similar issue on my rig (97 LX w/160K). I purchased it a couple months ago and did a coolant flush and put in a new Toyota thermostat as preventative maintenance. Coolant that came out seemed to have been changed right before I purchased the vehicle so I'm not sure of the condition of it before that. I have been driving it for about 3000 miles since then with no issues.

However yesterday on my way home it began to sound like it was misfiring when waiting at a stoplight. A few minutes later I saw that the temperature on both my Scangauge and the cluster was higher that normal and quickly began rising. I pulled into a parking lot right as the needle reached the red mark on the cluster and shut it off. I opened the hood and saw that the overflow tank coolant was bubbling (some of the coolant was coming out of the drain hose) and could hear the same going on in the radiator. Besides the coolant bubbling out of the reservoir hose I did not see any visible leaks in the engine bay or under the vehicle. I had an appointment to go to so I had someone pick me up and then take me back to the LX after the appointment. I wanted to try and get it home since I was only about 2 miles away. I opened the radiator and topped it off with 50/50, put the heat on max, and then proceeded to drive it home. On my short drive home (5-7 minutes max) the temperature rose very quickly almost making it to the red mark by the time I pulled into the driveway and shut it off. I also noticed that I was not getting any heat coming out of the vents the entire way home. Previously the heat worked perfectly.

I let it sit while I ate dinner and began thinking what could be the issue. I immediately thought the thermostat even though it had been replaced with a new one. I kept the old one as a backup, so I decided to take the "new" thermostat out and put the old one back in. The "new" thermostat I pulled out seem to be fine, at least visually. I filled the radiator back up with tap water (I planned on filling with distilled water and coolant later if it fixed the issue) and turned the truck back on. I noticed that the radiator wasn't "pulling" in the water like it had done when I flushed the coolant system the first time and that the heat was still not blowing hot when the truck was at operating temperature. I also noticed that the all the radiator hoses stayed relatively cold even at operating temperature. Leading me to believe that there is no flow in the coolant system. Lastly, the worst part, I saw that the truck was blowing more than the average amount of white smoke while warming up.

I know that a failed head gasket is a very likely and am prepared to deal with it if that's the issue. However, like most of us, I'd prefer if that's not the case. I've done a lot of work on my vehicles but I've never done a leak down/compression test, or have the tools to do one. So I'm considering all my options before buying the tools to try to the test myself or towing it to a shop to have them do it. Based on what I saw after swapping out the thermostat I think it's possible that my original radiator is clogged or that my water pump might have failed. I can purchase a Koyo radiator and Aisin water pump for around $200 and am wondering if this is worth a shot? or if would be smarter to purchase/pay someone to do the leak down/compression test? Let me know what you guys think.

 

[ccslider]

I would go to harbor freight and buy the coolant pressure tester. This screws on to the radiator in place of the cap and then you manually pressurize the system with a hand pump. You can look on your radiator cap for pressure rating. I would go somewhere around that. Usually 15 - 20 max.

Just mark the gauge and let it sit for awhile inspecting for and leaks.

If you come back awhile later and the pressure has dropped but you can't find any leaks the coolant may be pushed into the cylinder. I would pull the spark plugs and confirm this before trying to start the truck, otherwise you could hydrolock the engine and do some serious damage.

The head gasket can be bad on the exhaust side which pressurizes the cooling system and will push the coolant out of the overflow.

 

[EPIC Cruisers]

I would go to harbor freight and buy the coolant pressure tester. This screws on to the radiator in place of the cap and then you manually pressurize the system with a hand pump. You can look on your radiator cap for pressure rating. I would go somewhere around that. Usually 15 - 20 max.

Just mark the gauge and let it sit for awhile inspecting for and leaks.

If you come back awhile later and the pressure has dropped but you can't find any leaks the coolant may be pushed into the cylinder. I would pull the spark plugs and confirm this before trying to start the truck, otherwise you could hydrolock the engine and do some serious damage.

The head gasket can be bad on the exhaust side which pressurizes the cooling system and will push the coolant out of the overflow.

I didn't even think about buying a cheap tester from Harbor Freight. I'm about to pick one up on my lunch break and test it this afternoon. Seems pretty simple to do.