Overheating.....

Post by **jt74** » 30 Jun 2011, 04:44

Hey guys, hope you find yourselves well....

I'm really hoping someone can help me with this. My car overheated, Again. There are no leaks that I can see aside the small drips from what I think is the A/C. It doesn't smell like coolant anyway. Still, the expansion tank is not going below the min level. The fan is coming on like is should, no leaking from the radiator and the coolant line that was fixed last week is holding firm. Could my water pump be bad? Maybe the intercooler has something to do with it? I'm so lost........

I took out the thermostat last week and have been running the car without it since. I also have been using only water to fill the expansion tank. Could these two things cause the car to over heat? I drove it today about 50 miles in 89 degree heat with the A/C Blasting and made it to Waikiki with no problems. On the way home, ( a 22 mile drive at 10:30pm) I made it 3 miles from my house and it overheated. There was a 5 min bit of stop and go as they where doing road work. After I pulled the car over and shut it down I waited about 30 min, filled it back up with water, 1 quart of oil and drove another 10 miles, to my house then my other job. Seemed to be okay. The hood wasn't even warm.

Any and all help or suggestions to help me try to figure this thing out would be great. I just got a better gig but it is on the other side of the island and I don't think driving over the Pali is an option at this point. I really need that job and I don't fancy riding the bus.

Thanks.

John

p.s. Could the water pump be bad but not leak?

Post by **Juan62** » 30 Jun 2011, 05:08

First, you stated the coolant in the expansion tank does not go below the min level, but you are filling it with water. Humm...
Are your temp reading higher? Are you putting in distill water or tap? While the car is cold, look directly under the thermostate, you see a temp sensor. Start the car and run to normal temp (about 3-5 min). Shut off and check again for leaks. You are leaking somewhere if you filling up with water. If you going to use any water, Distill water only...no tap.
Replace the thermo with a (Whaler) brand.You would have to remove the timing belt cover to see if your water pump is leaking.

Post by **jt74** » 30 Jun 2011, 05:18

Yes. Distilled water. I have to refill it because when it get's hot it steams out of the top of the expansion tank from under the cap and I lose a good bit. The temp sensor should be working fine as I just changed that along with the cap about a month and a half ago and seems to be warning me at just the right time. ( It stays at right about halfway up the gauge, normal op temp, then rapidly move toward red when starting to overheat)

I'm thinking maybe it's coming from the weep hole and the reason is doesn't smell like coolant is because it's mostly water by now. Duh. The water pump was next on my list but I guess I'm going to have to do it sooner. I was just trying to narrow down what it could be and if not running the car with a thermostat had any negative affects. Thanks for posting Juan.

Post by **Juan62** » 30 Jun 2011, 06:23

JT; one more thing, it may be time to replace All coolant/expansion tank hoses too. Since you are going to change the water pump, make sure its Volvo OEM, Aisin, or Hepu water pump. Also, might as well change your timing and serp belts while you have things disassembled. Thats hat I'm going to do in the next 2 weeks. Oh, I would recommend to purchase two gallons of coolant from the dealer.

Post by **jt74** » 30 Jun 2011, 06:54

I really want to to the timing belt at the same time but the bulk of my bills are due at the beginning of the month. If I didn't just get this new job offer then I could have taken time off from the second job and bused it for a couple weeks. Unfortunately, I need the car working by the 11th so I am just going to have to go in for the timing belt after the 15th. Really sucks but needs to be done that way. Thanks for the tips though and I will definitely add the hoses to my order.

I was under the impression that the Zerex G-05 was a quality replacement for the coolant? Lee posted it I think... might be wrong though. The coolant from the dealer is wicked expensive I'm sure.

Post by **precopster** » 30 Jun 2011, 07:04

You need to run a gases check in the coolant. There are some great kits available at auto parts stores.

Something tells me you are getting overpressurisation due to leaking combustion gases and this is causing the overheating/boiling. Do this before you waste your time changing the water pump; impellers are brass if OEM.

Post by **jt74** » 30 Jun 2011, 07:08

Thanks a ton precopster. You see, that is something I would have never in a million years thought of. MVS is the shiznit!!

So this kit would be called a "Coolant gas check kit?" Sorry if that is a stupid question. lol

Post by **jblackburn** » 30 Jun 2011, 07:28

Erm...water boils way sooner than coolant. The fan doesn't cut in til ABOVE 212 degrees.

Get the water out of there.

Under a pressurized system, a 50/50 mix of antifreeze/water will boil at something like 270 degrees.

I use Zerex G-05 and it works just fine. It's a HOAT-certified coolant, which is what these cooling systems are designed for.

Post by **precopster** » 30 Jun 2011, 07:36

I agree with Justin on the coolant. Use a 50/50 mix or mix yourself from pure coolant with distilled water.

Take a look at this regarding checking for gases; makes it clearer than I ever will:

http://www.youtube.com/user/realfixesre ... YQHkWVULn8

Post by **jt74** » 30 Jun 2011, 07:47

Hey Justin.. Thanks for the input.

@ precopster. Yeah, that is a great link and definitely clears the picture up for me. Mahalo for taking the time brother.