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Discussion Starter #41
Happy Thanksgiving friends.

Guess what I'm doing? Yup, working on this thing.

Ok so I replaced the radiator and flushed the heater core again. Filled the coolant and bled it till a steady stream came out of the heater core hose.

240F, no fan and no additional cooling above 190. And another thing I'm noticing, the radiator isn't warm to the touch. Nor is the lower radiator hose from the thermostat. Should it be? Is it possible my new thermostat is faulty? Or that my lower radiator hose is clogged?

I'm completely at a loss now and I just want this done. Suggestions?
 

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Discussion Starter #43
Yes most of the system had been drained.

I don't believe anything is coming back through the expansion tank. Only the top radiator hose is getting hot but I didn't think the coolant ran that way. Maybe heat migrating from the engine down the hose?
 

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Just tuned into this, I'm starting to wonder about that water pump you got.
What kind (brand name) did you get? Plastic or metal impellar?

Have you scanned the car for any codes lately?
 

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JMHO on the 1.8t
I have seen crud caked onto the thermostats, so I suspect that clogged thermostats could restrict coolant flowing through the radiator. Remove the thermostat and flush out the engine & radiator by removing hoses.
Driving the vehicle about 30-35 MPH and you should not need the radiator fans since the air flow should cool the radiator. IF there is crud in front of the a/c condenser or radiator then things can run hot but the radiator hoses should be very hot and the electric fan should come on. I use some soft brushes to remove the debris.
Getting nice heat through the heater is good = core is allowing coolant through it and the water pump is functioning but if the demand on a "slipping" pump's impeller is too great then the coolant may not flow through the radiator at speed.
The impeller can be inspected with the thermostat removed.
A cracked cylinder head or defective cylinder head gasket could allow combustion gases to enter the cooling system and pressurize the cooling system. Maybe making the coolant hotter and/or allowing the coolant to enter the combustion chamber with the engine off.
When I see coolant contaminated with oil (bad oil cooler) I flush the entire system multiple times with some Dawn dish detergent and plain water with the engine running and the thermostat removed. Then flush it with plain water until it comes out clear. I guess I could use one of those flushing adapters, but I hate cutting up a good hose.
I have had good success with diluted CLR in a few different heater cores (sitting for 5 minutes) before flushing them out with my garden hose x 3 times.
 

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Discussion Starter #47
Thermostat is new. Water pump is new. Radiator is new. I've flushed the heater core twice with CLR, including leaving it overnight. Top hose is getting hot, bottom one is not.
 

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Yes most of the system had been drained.

I don't believe anything is coming back through the expansion tank. Only the top radiator hose is getting hot but I didn't think the coolant ran that way. Maybe heat migrating from the engine down the hose?
Not much else I can think of unless the head and block are clogged up.

When Tortelius mentioned the little return line...it should be shooting a steady stream into the tank, especially once the engine has warmed up.

There are only two connections to the lower radiator hose. The thermostat housing and the reservoir. Yes, it's a new thermostat but that could be a problem, still. It truly sounds like you are getting no flow out of the block and into the radiator at the bottom. I always test mine before install by dropping it into boiling water to see if it opens. I believe the stock heat rating is about 189°F.

The coolant pipe on top of the intake manifold running front to back should be hot as that is coming from the coolant flange at the back of the head. If you have one of those laser thermometers, see what the temp of the pipe is at cluster/scanner indicated operating temps. It should be pretty close to the sensor reading.
 

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When Tortelius mentioned the little return line...it should be shooting a steady stream into the tank, especially once the engine has warmed up.
That's a good point. Check to see if you have a stream of coolant coming out of that little hose that attaches on the top of the coolant reservoir. If you have flow out that rubber tube your water pump is working.

You shouldn't have flushed the system with a brand new radiator. Chunks of whatever may have come loose and lodged in the brand new radiator.
I would check the flow of the radiator by running a water/garden hose into the top radiator hose fitting and look to see how much water comes out the bottom.
If the radiator is flowing water like it should, it will be able to handle a surprising amount of water from the garden hose. That's kind of a vague statement because water pressure hose diameter size and all of that. But, somewhere around 1/4 to halfway on the hose faucet is a round about estimate.

Just an after thought because it was already done, but you should never use CLR to flush the cooling system. CLR is very corrosive and attacks aluminum. The head and radiator center section is made of aluminum.
 

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Discussion Starter #50
97870

Anyone have any idea what this broken plastic hose is? For reference that's the thermostat housing opening on the left and the orange thing is the dipstick tube.
 

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Hopefully the heater core was still original. The aftermarket replacements are made of aluminum.
 

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What could it being broken do to my engine?
It's also known as oil breather tube. Mine was cracked like that for a while and caused rough idle (I replaced other parts of PCV at same time so I can't be 100% sure). It did not cause engine overheating. It's possible your PCV system is clogged and you may have some work ahead of you.

Specifically regarding that part (and don't fool yourself, it will never just be one part) it was a PITA to replace because the intake had to be disassembled / pulled back since otherwise there was no way to put direct downward pressure to force the new one in. Worth mentioning that I bought an aftermarket part at like $20 bucks, not OEM, which may be why I had so much trouble.

After pulling back intake steps are: Tape over the intake ports (like the blue painters tape in my pics below) so nothing falls in. Next remove the old one. It has or will crumble or burst and you will have to vacuum out the pieces from the hole. Remove the oil dipstick tube. Next insert the new one with direct downward force like basically put your body into it and rotate it back and forth. If it's facing the wrong direction that is fine because once it's secured you can swing it around. I did mine without removing the metal pipe in the back. You can see all this in the thumbnails below (click for full sized pics):

oil breather tube 1.jpg oil breather tube 2.jpg oil breather tube 3.jpg oil breather tube 4.jpg

and once it's done it looks like below, (with all the connecting pieces also bad replaced except the back metal pipe which was fine once cleaned):

oil breather tube 5.jpg




Also +1 to what was said earlier about measuring the coolant temp or engine temp using one of those thermometer pointers. The coolant temperature sensor on the passat (the one behind the engine not the one on the radiator) is a DUAL sensor, meaning it has two sensors in it and it's possible one may fail and one may not. I think one is the temp it shows in the gauge and the other is the one used by the ECU. I have no idea which one Torque app shows you. In other words just because it's showing you one temp the ECU may use the other temp. I don't know a lot about that though hopefully someone else does and can explain it better.
 

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What could it being broken do to my engine?
Common problem. The breather tube gets brittle over time and disintegrates/breaks.
I'm surprised you don't have any codes. That would cause a pretty rough idle. Scanning with VCDS would produce a complete accurate scan of the vehicle. By that I mean, Generic scanners tend to pickup the active codes causing the CEL. VCDS scans every module individually and posts what codes are stored whether or not it triggers the CEL.
 

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Discussion Starter #57
It's also known as oil breather tube. Mine was cracked like that for a while and caused rough idle (I replaced other parts of PCV at same time so I can't be 100% sure). It did not cause engine overheating. It's possible your PCV system is clogged and you may have some work ahead of you.

Specifically regarding that part (and don't fool yourself, it will never just be one part) it was a PITA to replace because the intake had to be disassembled / pulled back since otherwise there was no way to put direct downward pressure to force the new one in. Worth mentioning that I bought an aftermarket part at like $20 bucks, not OEM, which may be why I had so much trouble.

After pulling back intake steps are: Tape over the intake ports (like the blue painters tape in my pics below) so nothing falls in. Next remove the old one. It has or will crumble or burst and you will have to vacuum out the pieces from the hole. Remove the oil dipstick tube. Next insert the new one with direct downward force like basically put your body into it and rotate it back and forth. If it's facing the wrong direction that is fine because once it's secured you can swing it around. I did mine without removing the metal pipe in the back. You can see all this in the thumbnails below (click for full sized pics):

View attachment 97872 View attachment 97873 View attachment 97874 View attachment 97875

and once it's done it looks like below, (with all the connecting pieces also bad replaced except the back metal pipe which was fine once cleaned):

View attachment 97876



Also +1 to what was said earlier about measuring the coolant temp or engine temp using one of those thermometer pointers. The coolant temperature sensor on the passat (the one behind the engine not the one on the radiator) is a DUAL sensor, meaning it has two sensors in it and it's possible one may fail and one may not. I think one is the temp it shows in the gauge and the other is the one used by the ECU. I have no idea which one Torque app shows you. In other words just because it's showing you one temp the ECU may use the other temp. I don't know a lot about that though hopefully someone else does and can explain it better.
Thank you. That's all very helpful! This free car is turning into a much bigger project than I had hoped.
 

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Discussion Starter #58
Common problem. The breather tube gets brittle over time and disintegrates/breaks.
I'm surprised you don't have any codes. That would cause a pretty rough idle. Scanning with VCDS would produce a complete accurate scan of the vehicle. By that I mean, Generic scanners tend to pickup the active codes causing the CEL. VCDS scans every module individually and posts what codes are stored whether or not it triggers the CEL.
Believe it or not it idled nice and smooth!
 

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Full PCV writeup, credit to jdts:

DIY: 1.8T ATW PCV Breather Overhaul, Injector Cleaning & Oil Filter Gasket

It's for ATW not AWM but pretty similar. If you've exceeded your budget on the other things you might get away with some silicone self-fusing tape (like "rescue tape") stretched and wrapped over the hole. Silicone tape only binds to itself when absolutely clean though which will be difficult in that area.
 

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Discussion Starter #60
Thank you. I have AWM? Does that mean This won't fit since it's a 2005? Should I be looking for a different pcv valve?

Nope budget is not exceeded yet. I'd rather do it right.
 
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