A bit of a head scratcher! Sounds like the thermostat stuck closed or an air bubble still in there somewhere. Might be worth checking the coolant bottle cap. If the seal is gone, the system won't pressurise enough to push coolant past the thermostat. Good luck with it. Let us know what you find!
Cooling system trouble
I have a 2002 vw beetle with the 1.8 turbo in it. The car blew a hose while my wife was driving it to work. I fixed the hose and got it going again. About 15 minutes into the ride home she started to overheat. I got it it home and it seemed like it was the t-stat. Replaced it and everything seemed to be working fine. While bleeding out the system I had trouble getting heat, but that eventually worked it self out. My wife drove it for 2 days and then she called me and said her heat didn't work. She drove another couple of hours and then her car overheated again. I took out the t-stat and tested it and thought well maybe it had air still I the system. Got it going again and the system seemed to be working fine again. I could see the water level would rise and lower in the reservoir and the water pump seemed to be flowing fine. But could not get heat again. Drove it a couple of miles and it overheated. This time the water pump went. Had coolant all over the timing belt. I pressurized the system and saw that it blowing out of the water pump. I replaced that and now I can not get the coolant to flow. I could have a faulty t-stat but is there anything else I could check, and why does the heat not work? If I my auxiliary water pump fails would it cause overheating. Also the upper radiator hose gets hot but the other ones don't . Not even the smaller hose that goes from the upper radiator hose to the auxiliary pump or the two hoses from the heater core. Driving myself nuts with this. I have had refill the coolant several times for other issues and have never had a problem bleeding the system.So I don't think there's air trapped, but I can't figure this out
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blockage
common issue is blockage in the small hoses going to and from the reservoir. As long as there is no blockage these beetles don't get air pockets because all the bubbles float to the top and the reservoir is mounted at the highest point of the coolant system.
common issue is blockage in the small hoses going to and from the reservoir. As long as there is no blockage these beetles don't get air pockets because all the bubbles float to the top and the reservoir is mounted at the highest point of the coolant system.
I found that I have flow going into the heater core but nothing coming out. I guess that would mean that the heater core is clogged. Would that cause the car to overheat? By not allowing the coolant to flow. I plan on just bypassing it for now, but if anybody has any thoughts I need it. I did have the lines disconnected, could I have hooked them up wrong?
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heater core?
The heater core? I don't think so. how are you checking the engine temperature? try the cheapo ELM32 obd2 reader off ebay for about $20-25 and a cell phone to monitor the coolant temperature before you burn up that engine. I use my iphone4 and the app. Dashcommand to monitor my coolant once in a while.
Are you sure both fans are blowing correctly? Your car would still run a little warm without one of the fans as long as you keep moving. If you stop the car for any reason then the coolant temperature would immediately in a few seconds start to rise and eventually overheat depending on how long you drive it like that. To check both fans push the A/C button on while the ignition key is in the ON position and both fans should run low speed, if not there is one of your problems.
The heater core? I don't think so. how are you checking the engine temperature? try the cheapo ELM32 obd2 reader off ebay for about $20-25 and a cell phone to monitor the coolant temperature before you burn up that engine. I use my iphone4 and the app. Dashcommand to monitor my coolant once in a while.
Are you sure both fans are blowing correctly? Your car would still run a little warm without one of the fans as long as you keep moving. If you stop the car for any reason then the coolant temperature would immediately in a few seconds start to rise and eventually overheat depending on how long you drive it like that. To check both fans push the A/C button on while the ignition key is in the ON position and both fans should run low speed, if not there is one of your problems.
Well the cars been idling for about a 1/2 hour and has not overheated. I do have a few concerns though. I do not notice the level rising and lowering when the t-Stat opens. Should it? But all the hoses are hot. I also still have no heat. If I leave the heater core hooked up and it's clogged will that damage anything else? Should I bypass until I have it tested?one line to the core is hot and one line is warm.
overheat
One problem at a time. I would fix the overheating issue first because you don't want to burn up your engine. I would monitor the coolant temperature some how to see what actually is going on with the system instead of troubleshooting in the dark. Once the coolant system is solid I don't think you would see the level in the reservoir change that much even when the thermostat is cycling. Okay so you idle for 30 minutes and no overheating, I would have driven it around for a while to see if it would overheat. When the blend door go's bad it also does not produce heat at the dash.
One problem at a time. I would fix the overheating issue first because you don't want to burn up your engine. I would monitor the coolant temperature some how to see what actually is going on with the system instead of troubleshooting in the dark. Once the coolant system is solid I don't think you would see the level in the reservoir change that much even when the thermostat is cycling. Okay so you idle for 30 minutes and no overheating, I would have driven it around for a while to see if it would overheat. When the blend door go's bad it also does not produce heat at the dash.
Ok so I drove the car and put about 30 to 40 mIles on it with no overheating issues. So hopefully I'm good. The heat on the other hand! It goes on and off. It seems like when I'm cruising at low rpm it cools down and when I bump up the rpms and push it it heats up. Thoughts
I think the impeller is broken on your water pump.
I hope not. I Just replaced it like a day ago.
blend door
Okay, so it sounds like the overheating problems is solved. One reason to check for no heater blowing is the Blend door. Check that.
Okay, so it sounds like the overheating problems is solved. One reason to check for no heater blowing is the Blend door. Check that.
Yeah, oops, I saw that you just did the pump right after I posted.
I'd also get the scanner on it to check/monitor the actual coolant temps for a few days.
I'd also get the scanner on it to check/monitor the actual coolant temps for a few days.
So my wife has been driving the car for about 2 days and this mourning the reservoir is empty. Yesterday her low coolant light did come on but then it went off once it heated up to operating temperature. I can not see any leaks nor do I smell anything in the cab. Thinking maybe the heater core might be leaking because I have no heat. She said that she had no heat until she got up on the highway and then it started working. The only thing I can think of is a head gasket. I did do a leak down test and everything seemed fine. I could be performing the test wrong and it was a cheap set that I bought. I think my next step is to do the test again and maybe pressurize the coolant system to see if I can find any leaks. The only thing that I don't understand is that the car is running excellent. It's actually running better since I put on a new timing belt. I think the dealership was off on the timing. I have no white smoke out the exhaust and I have no coolant in the oil or in oil in the coolant. I even checked to see if there was exhaust fumes in the coolant and that test came back negative. Wouldn't I have some type of symptoms with a leaking head gasket?
It may be leaking out of the aux water pump, or one of the coolant lines. Both went on our 1.8T. The metal line along the frame on the passenger side is really common to go. Get under the car and look for the pink crust that shows the leak area.
reservoir
Dude, I told you how the reservoir level is displaced by air in the system after you refill the system. You don't listen to what I'm telling ya. This is my last help in this thread , good luck man.So my wife has been driving the car for about 2 days and this mourning the reservoir is empty. Yesterday her low coolant light did come on but then it went off once it heated up to operating temperature. I can not see any leaks nor do I smell anything in the cab. Thinking maybe the heater core might be leaking because I have no heat. She said that she had no heat until she got up on the highway and then it started working. The only thing I can think of is a head gasket. I did do a leak down test and everything seemed fine. I could be performing the test wrong and it was a cheap set that I bought. I think my next step is to do the test again and maybe pressurize the coolant system to see if I can find any leaks. The only thing that I don't understand is that the car is running excellent. It's actually running better since I put on a new timing belt. I think the dealership was off on the timing. I have no white smoke out the exhaust and I have no coolant in the oil or in oil in the coolant. I even checked to see if there was exhaust fumes in the coolant and that test came back negative. Wouldn't I have some type of symptoms with a leaking head gasket?
I am listening to you. It just seems like 2 days is a long time to work the air pockets through. I'll try to refill the system and drive it. Don't bail on me yet. I have to figure this one out. I'm just concerred because I have worked on a lot of vehicles and this one is driving me crazy.
When I had my timing belt done, it took a few days for the last bit of air to work its way out of the system.
Smileybugs correct it may take several cold hot cycles for all of the air to work out of the various nooks and crannies in the engine and head, because the thermostat is not at the top of the system like most domestic cars. That's why shops use a vacuum fill system. It lets them vacuum check the system, remove all of the air and completly fill it in one operation.
I will elaborate on something esse10 said earlier about a blockage in one of the coolant reservoir lines. I have a turbo-s that had on and off over heating issues and it turned out to be a blockage in an orfice located in the small line going into the side of the coolant reservoir. Turns out it was a small piece of water pump impeller. It wouldn't over heat all the time. Just at random. About drove me crazy but once I found the blockage and removed it I never had another problem. You can take that line off the tank and have someone crank the engine and idle it up to around 2000 rpms and you should have some kind of flow from that line.. Especially if it jut had a water pump put in it.. If there is no flow then there is a problem there that should be resolved. I never had any problem with over heating until I done the regularly scheduled water pump and timing belt and then it all started. Must have stirred something up in the process of flushing the cooling system..
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