NewBeetle.org Forums banner

1 - 15 of 15 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
Hello all. I have a problem and I was hoping someone can help me. I have a 2002 VW Beetle GLS with the 2.0 engine. I am having a overheating problem and I have narrowed it down to one problem. The small coolant return line that goes into the top of the reservoir from the throttle body is not flowing any coolant at all. Even when the engine is running and at high revs. It is completely blocked. I checked the line back to the throttle body, and out the TB to the right side of the engine block and that's where the block is. It's in the block. From there I am stumped since all of the lines including the throttle body is clear. I also have replaced my thermostat (after verifying it works by boiling it) and have verified my water pump isn't damaged. The radiator doesn't seem blocked but I'm not sure. It overheats after about 15-20min of idling and coolant will start bubbling out the reservoir. Any help would be greatly appreciated. Thanks
 

·
Registered
Joined
·
2,215 Posts
Sure sounds like the water pump. How did you verify the water pump was OK? Does the heater work?

With the wrong coolant in there you could have sludge buildup as well.

The hose that runs through the throttle body to the expansion tank starts off at the cylinder head. You should be able to remove the hose from the cylinder head and see if the passage is clear.

If your timing belt and water pump are original, they are certainly due for replacement.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #3 (Edited)
Thanks redd99 for helping out. When I replaced the thermostat I inspected the water pump impeller and they were tight and undamaged. However, I do believe it is the original water pump and at 88,000 miles I will be replacing that pretty soon. Would a broken water pump cause that kind of impenetrable blockage like that? I mean I can't even blow air through it. Also the heater does work very well.
 

·
Registered
Joined
·
2,215 Posts
The water pump impellers will usually detach from the shaft that drives it so the impeller will be intact but spin on the shaft. This leads to weak flow through the cooling system even with no blockage.

Mixing green coolant with the original VW G12 coolant is known to cause a sludge buildup which may well be your main problem. You could try one of the cooling system cleaners (acid based, not the "flush") and see if that will cut through it. After using the cleaner I would do a couple cycles of drain, backflush and fill with distilled water to get all the cleaner out. Then fill with either G12 or G13 and distilled water at 50/50.
 

·
Registered
Joined
·
758 Posts
If it's the original water pump, I'm guessing the timing belt is original too. When you replace both of those, you should also replace the timing belt tensioner, thermostat, acessory belt, and coolant. I bought a "timing belt kit" online that included all of those parts.

I did the job myself, so I also bought the tool for the timing belt tensioner. There are several "how to" guides for this online. In addition to reading/watching some of those, I also bought the Bentley manual for my car. That helped too.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #6
Thanks Jeff2 for the info and I do plan on replacing those things. Do y'all have any idea what could me causing this blockage at the block? Have y'all heard of this problem before?
 

·
5/23/10 <3
Joined
·
11,155 Posts
Have you mixed coolants?
 

·
mike03 2.0 vert
Joined
·
100 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #9
I'm pretty sure the coolant was mixed as it had bright green coolant in it when I purchased it. They could have flushed it completely before putting the green in but I don't know. I read that thread prior to posting and was excited to see someone having successfully fixed the problem I had but my blockage goes past the throttle body all the way to the engine block (driver side near the battery).
 

·
Registered
Joined
·
3 Posts
I have a 03 beetle convertible also with this simillar proplem..good water pump,good thermostat but no coolant returning to resovoir...its a 2.0L engine by the way..sorry..I followed the hose from the bottle to throttle body and right up to the head..all hoses were clear..when I got the the fitting on the head where the hose attaches to it seems blocked...I tried blowing air into it but nothing would enter...is there a check valve in there...car has no heat..took it to dealler and they put thermostat in it and no diference...there is no return flow,or should say no flow that I can see..lower rad hose cold at opperating temperature but top rad hose hot,but not burning hot..I think something to do with that fiting in the head is blocked...kind of stumped here..bought the car last year had no heat hardly..2 thermostats later still no heat but don't see serculation...
 

·
Registered
Joined
·
2,215 Posts
You're on the right track. The line from the head to the reservoir needs to be clear for the air to purge and allow the coolant to flow. The problem is often corrosion or sludge blocking the fitting in the head. There should be an open passage. Try using a piece of stiff wire or small rod to open up the fitting.
 

·
Registered
Joined
·
7 Posts
I cant get anything in there, it doesnt feel like it will give at all. I'm going to need a hammer and something strong to unclog it if I do, is that normal? I mean can the clog feel like cement in there?
 

·
Registered
Joined
·
2,215 Posts
Posting this video here for reference:


Try working a drill bit around inside the hose nipple. It is probably filled with hardened debris from not having any flow for a long time.
 

·
Registered
Joined
·
7 Posts
I cant get anything in there, it doesnt feel like it will give at all. I'm going to need a hammer and something strong to unclog it if I do, is that normal? I mean can the clog feel like cement in there?
HuIt goes in alot further than the hi ose nippl

Posting this video here for reference:


Try working a drill bit around inside the hose nipple. It is probably filled with hardened debris from not having any flow for a long time.
Posting this video here for reference:


Try working a drill bit around inside the hose nipple. It is probably filled with hardened debris from not having any flow for a long time.
It goes alot deeper than the nipple. And how do you know if I'm hitting something inside there of not,? Is it hollow even I side the block? So I can go in as far as I want to go? and if its blocked unblock it. ? Does it turn?
I cant find anything on this and I've never had the head off to see Inside a volkswagon motor
 
1 - 15 of 15 Posts
Top