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Discussion Starter #21
Got everything put back together last night. Proud of myself, not a single bolt leftover!

However, pressurized the coolant system to test and there's a small leak. I believe I narrowed it down to the temp sensor in the flange. Of course it's not in a simple place. Ordered a new sensor and gasket. I hope that's it. I would hate to have to remove the flange again. Way too much work undoing almost everything I did just to get to it.

You mentioned replacing the coolant flange and my two cents would be to replace it with the cast aluminum replacement from Urotuning it is relatively cheap and is said to last 250,000 miles. I was doing the flange replacement and had already bought the oem replacement part and came across the cast aluminum one and just got that and sold the other one on Craigslist. Once again just my two cents. Good luck!

Oh and cometic makes a awesome head gasket, in my opinion the best you can buy, you definitely pay for the quality, but it can fill in minor perfections and if needed change your Compression ratio.
Maybe you were right. :( But I did put in a brand new OEM quality part. I just hope the new flange isn't the problem and the new sensor does it.
 

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Sometimes the clip that holds the sensor in feels and looks like it went on right but will go on top of one side of the sensor and under the other side of the copper top and causes a small leak. As you probably know it’s a pain trying to push the sensor down on the o’ring and seat it right from that angle. I would look at that before pulling everything apart.
 

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Discussion Starter #23
Sometimes the clip that holds the sensor in feels and looks like it went on right but will go on top of one side of the sensor and under the other side of the copper top and causes a small leak. As you probably know it’s a pain trying to push the sensor down on the o’ring and seat it right from that angle. I would look at that before pulling everything apart.
That may have been the case. I took the valve off the top and moved a couple lines to make sure I properly seated the new one and it seems to be fine now. It's weird because I put the old one in the flange while I had the head on the bench. Mysteries.
 

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Indeed! Well at least the sensor did the trick.
Congratulations! I hope that’s the end of the Mystery for now. I love these cars, but they are definitely full of Mysteries.
 

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Congrats BradfordJames! Sounds like you got it running and I know from personal experience that the first time you dive in and do a job like this it's very satisfying to get it running well afterwards.
 

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Discussion Starter #26
Congrats BradfordJames! Sounds like you got it running and I know from personal experience that the first time you dive in and do a job like this it's very satisfying to get it running well afterwards.
Thank you. It's running. Whether it's fixed I do not know yet. Just letting it idle for a bit in the garage for now. Burn off all the crap that got everywhere and watch for leaks.
 

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Discussion Starter #27
Ok I'm lost. Everything is back together and it's running great. No leaks or anything. Good heat at the vents, but it's still getting hot and it seems like if the thermostat ever opened it only goes it for a few seconds before snapping closed again.

I bought a thermal camera to try and see if I had another issue I couldn't find but I can't see anything abnormal. Any thoughts where I should point my camera to check?

98431

This is a photo of the thermostat housing tube with the engine at 230*F. It's obviously not open.
 

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Discussion Starter #28
98435

Should this tube be as hot as the rest of the engine? Looks like it's going to the turbo. It's 80*F cooler than the temperature sensor is seeing.
 

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That tube is the coolant return from the turbo, it's not far after the water pump. It should be warm, but would be hot if driven hard. I also suspect the calibration on your readouts from the engine. What are you using for the readings? Has it been calibrated?
 

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Discussion Starter #30
It's a brand new coolant sensor and I'm getting the data through my scan tool from the obd port. The thermal camera and my laser thermometer concur with the temperature the new sensor is seeing.
 

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Yes , the turbo is fed from the block with a short u-shaped tube with banjo fittings on the end, you might want to check the hose in the pic and make sure you have flow thru it, it should be the same temp as the internal temp of the engine or higher since the turbo would not be cooling it. Coolant flowing thru the turbo from a coolant circulation perspective is of high priority. The pipe that returns coolant to the engine to the aft of the thermostat housing (next to the crankcase elbow) should be dang close to the engine temp, it is designed to flush fluid over the thermostat to encourage the thermostat to open. The thermostat does not open like a door it opens proportionally to the temperature differential between the radiator and the engine.
 

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Discussion Starter #33
I can confirm that tube is clear. I took it off when doing the head gasket to check it. I'm starting to wonder if maybe I have a blockage in the turbo somehow. Could that be a thing?
 

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yes, and very possible since its connection is a "banjo" type fitting,more likely clogged at the fitting vs. in the turbo itself.
 

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It's a brand new coolant sensor and I'm getting the data through my scan tool from the obd port. The thermal camera and my laser thermometer concur with the temperature the new sensor is seeing.
Just wanted to make sure as I've seen bad equipment before.
 

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Discussion Starter #37
Does anyone have actual experience running without a thermostat? What temperature should I expect the car to run at?
 

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as in, thermostat stuck open? It will run cool to cold and the temperature will depend on the ambient air temp, how fast the car is moving and how much load is on the engine. My guess.....120ish.
 

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It depends on the outside temps. I had one down here that ran 140 and it dumped enough fuel to ruin the cat. In winter up north, it would be worse. I have seen people ruin a cylinder due to constantly running cold.
 
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