[mikedigsrock]

Hi, I'm a courier and drive about 100 miles daily in my city. I added Bar's Leaks Cooling system stop leak last week, which worked. Now I'm catching the temp gauge climbing to about 65% each morning after about 5 minutes of driving and after about 10 seconds it goes back to normal. It also occurs when I stop at red lights but infrequently. It happens about 8 times a day, but it only lasts for about 10-20 seconds. Did the stop leak gum up the thermostat?

 

[Automender12345]

Why did you add stop leak? You could have partially plugged the radiator. Are the fans kicking on?

 

[mikedigsrock]

Why did you add stop leak? You could have partially plugged the radiator. Are the fans kicking on?

We've added stop leak a few times over the last 5 years. It was my son's car but he moved out of state and dumped the car on me. He said it was a lemon and he was right lol. Yes, the fans are kicking on. 99.9% of the time the temp gauge is 45%. I just catch it rising to 65-70% when I stop at red lights, then the temp drops to normal in about 10 seconds. I stop hundreds of times a day, and it only happens about 8 times. I also drive for several hours and the temp gauge never goes up.

 

[Automender12345]

We've added stop leak a few times over the last 5 years. It was my son's car but he moved out of state and dumped the car on me. He said it was a lemon and he was right lol. Yes, the fans are kicking on. 99.9% of the time the temp gauge is 45%. I just catch it rising to 65-70% when I stop at red lights, then the temp drops to normal in about 10 seconds. I stop hundreds of times a day, and it only happens about 8 times. I also drive for several hours and the temp gauge never goes up.

Why did you add stop leak?

 

[mikedigsrock]

Why did you add stop leak?

The same leak returns every year. It's hard to see the source, but my guess is the water pump. I used half a bottle of stop leak a few months ago trying to be conservative, but it didn't stop the leak completely, so I added a full bottle last week. It worked. I drained 2 gallons of coolant and replaced it, too.

Today I noticed the main times the temp gauge goes up is after I start the car. I'm a courier so I'm shutting off the engine every 15 to 20 minutes to pick up packages then restarting the car to make the deliveries, which usually also takes about 15 minutes. If I just drive around for an hour or more without shutting off the engine the gauge stays steady at 45%. I assume the thermostat closes when I shut off the engine for a few minutes, which is why I suspect the thermostat.

 

[helifino]

If it's coming from the water pump, it's a warning sign you really should heed.

 

[mikedigsrock]

If it's coming from the water pump, it's a warning sign you really should heed.

That's a near future project along with the power steering pump. I've pretty much replaced everything else. Not sure if it's the source of the leak though. Never would drip while I was watching. Could be the timing cover or even a hose. Last week while out making deliveries the car was overheating. I pulled over and checked the fluid. It was low, so I added a gallon of coolant. It took nearly the entire gallon. I checked under the car and saw a small puddle about 6-8 inches from the front passenger side tire. I had stop leak in the trunk so I added it. After about 20 minutes the leak had stopped. In hindsight I wish I would've driven home before adding the stop leak so I could've jacked up the car and found the leak. Now I'll have to wait for the stop leak to wear out.
Does it sound to you like the thermostat is sticking?

 

[Automender12345]

Good possibility the leak is the timing cover gasket which happens around 130k miles. Could be a sticking thermo but I only had one 40 years ago but it stuck close permanently. Did you replace the thermo and what brand. Seems like Motorcraft brand is better in these cars and doesn't give the consistent swings that cheaper ones do.

 

[mikedigsrock]

Good possibility the leak is the timing cover gasket which happens around 130k miles. Could be a sticking thermo but I only had one 40 years ago but it stuck close permanently. Did you replace the thermo and what brand. Seems like Motorcraft brand is better in these cars and doesn't give the consistent swings that cheaper ones do.

I really wanted the Motorcraft but can't get it locally and need to get the car fixed so I took the walk of shame to Autozone and bought the Duralast Gold. Just got home about 15 minutes ago so the car's hot. Debating whether I have enough time to do it before dark or if I should tackle it in the morning. I'm old and don't do these types of things fast lol. I vow to report back when it's fixed. Makes me nuts when people don't return and post their results.

 

[mikedigsrock]

It was the thermostat. All good!