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What does this sound like to you?

I had the engine rebuilt 1 1/2 years ago in the summer. At the time I never bothered to check to see if the heater worked. Winter came and heater blew cold air at idle. When I would drive, it would blow hot. The performance shop that rebuilt my motor said I probably had air in my coolant line. I purged accordingly. It temporarily fixed the heater. Summer came and I no longer needed the heater. Winter is back and I'm using my heater now and its still doing the same thing, however, this year is different. PLEASE NOTE: I was stuck at a train stop. I was idling while the heater was blowing cold air and I looked over at the temp gauge and it was close to the "H" spot. Train left and I started driving and the temp gauge went back to normal. I drove the car home and let it cool off over night. I went to purge the air out of the coolant line again. For those that understand how this is done, I won't explain, for those that don't know, oh well. I had the heater running full blast and I heard the fans kick on and all of a sudden the coolant started flowing out the top of the radiator and the temp gauge skyrocketed. The car is down at a local mechanic and he put in a new thermostat and that isn't the problem as the car is still overheating.

What does everyone think?

 

Heater core?

 

Thermostat.

 

still sounds like air in the system. but if its at a shop then they should be able to take care of it.

 

crap, it wasn't your thermostat....

 

Pardon my ignorance, but what makes you suggest the heater core? My uncle is thinking the same thing.

 

How could air in the system cause the coolant to come up out of the funnel on top of the radiator? Its as if the coolant couldn't continue to circulate.

 

Hey. Didn't see that you were in Louisville. I live across the river. What shop did you take it to?
Also, since you're blown, you might want a lower temp thermo. I just searched and found a Nismo that opens at 154 instead of 170.

 

Is the coolant level in the resovoir staying at the full line when cold or does it keep going low?Did you check the "weep"hole on the water pump?(You might refer to the weep hole as something else so if the terms not working for you ill explain)-did you replace the thermostat?

If you'd like my opinion I need all ?'s answered.
Hope I can help

 

1. I don't know. I didn't check.
2. I didn't check the weep hole.
3. Thermostat was replaced at mechanic. The thermostat didn't help according to the mechanic. Air is getting in somehow.

 

Local mechanic. Nothing special. Yeah, I heard that the Nismo has a lower operating temp as well. Do you have any recommendations as to some shops in the area. How far are you from Louisville? I live in La Grange on the I-71 NE of Louisville.

 

No real recommendations for shops. I'm still taking mine to a dealer (Neil Huffman). I live in Clarksville, IN and work in Louisville. I just got off of the phone with a friend that lives in LaGrange. Small world.
Maybe your car just has the Ohio Valley cruds!

 

I had the same problem last year and it drove me crazy....starts by not having enough fluid in the overflow resivor (sp?) and air gets sucked into your system when you go around a corner or something.

You didnt explain how you blead the air out or if the cap was off, but you shouldnt have the radiator cap off when you're bleeding the air out. Thats what the overflow tube that runs along the top of the radiator is for.

There's a little plastic screw thing to the right of the battery compartment (left of the engine towards the back) that you unscrew and it bleads there. Its not a normal "traditional" looking screw; it has a circle/plastic washer molded w/ the screw. (if I remember correctly)

Make sure you have enough in the reserve to keep the system full, and dont drop that plastic screw in the engine compartment like I did while I was at a gas station...it'll ruin your day...trust me Squeeze the thick coolant tubes cause air gets caught in them....i blead mine several times a day for like 2 days to get all the air worked out. Its been fine since.

 

They did a flow test on the radiator. Flow is fine. Overheating still an issue.

 

If you check the first two we can diag from there.The weep hole is under the water pump and is a hole that will let the coolant out when the seals/bearings start going in your water pump.
Top your resovoir off when the engine's cold and check it every day for a week.If you have any friends who are mechanics there's a tool kit called a coolant pressure test kit.You degrease the engine so its clean,use the tool to bring the cooling system pressure to operating pressure and see if the system is losing pressure.and if so is it external or internal.You could have a coolant hose leaking or even a headgasket besides the other problems mentioned so it'd be good to figure out what you have before it turns into a bigger problem.You need to find the cause before you try any repairs.Let me know and get a haynes repair manual from autozone or advanced auto.

 

Just got final word from them. They got all the air out of the system. Ran a flow test with clear tubing and the flow stopped and air was getting back into the system. They did a coolant pressure test and said that there was no external leaking. They said possibly blown head gasket or worse! NOT THIS **** AGAIN!!!! They said that they have this kit that attaches to the coolant line and that when air passes by it, it'll be drawn up inside of this contraption and inside this contraption, there is a chemical dye that will turn colors if there is carbon dioxide present in the system. If that is the case, then there will be some issues on these boards as this car has been babied since it was rebuilt. I also made sure that these problems were documented since last year.

 

Well, good news. After 4 days there and all these test, it turns out that the air is not contaminated carbon dioxide (monoxide?). They decided to do a vaccuum on the coolant line that pulls all the air out of the system and now the car is running fine and the heater is working. I need one of those vaccuum systems. They said that they are going to keep it over night for some more observations just to make sure that it is safe.


I'm as happy as a clam.


I didn't want to say this, but the reason why I was so concerned about this being my motor is that I'm still paying off my credit cards for this motor and more importantly, we are in the process of adoption which we will be getting our little girl in the middle of December and as everyone know... Adoptions are NOT cheap. Thanks to everyone that chimed in here, whether the suggestions were from the hip or whether they were educated suggestion. Thank you. That is why we need to continue to respond to other peoples cries, because even if it doesn't help with the car, it still makes you feel like people care. See ya around the boards!

 

Cool! On the car and especially the kid.
Pics of the little one as soon as you get 'em.

 

glad you got it straightened out, you will see your adoption money returned in February.

 

I've read the posts earlier and my question is. When my car's temp is at about 75%-80% High, I turn on my heater and I get cold or normal air. No heat at all. I just had my radiator replaced and after driving 4 miles from the shop, the temp. level goes from 25%-75% in less than 2 minutes.
Did you have the same problem username?

I hope that this is something that a thermostat can fix.