2003 Jetta Overheat Problem..Advice needed!!

Hello all!

I have a 2003 Jetta with 2.0l engine (62k miles) that is overheating. Here are the symptoms:

  1. Fan does work and will come on at 190 degrees or a little higher.

  1. Top radiator hose gets hot to the touch.

  2. Bottom radiator hose is COLD..

  1. I also get no heat.

This is a solid failure.....

I'm not sure of the direction of coolant flow in VW's, but past experience with other cars tells me this is a stuck closed thermostat.

Yes? No?

Is there some other item unique to the VW that typically causes this kind of a problem? TIA Charlie

Reply to
Charlie
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waterpump needs replaced

Reply to
Lost again

Well to answer my own question, it's not the thermostat. I pulled it and tested in pot of boiling water and it's fine, but I replaced it anyway.

Same problem...

I think the water pump is shot.

It figures, 4000 miles past the powertrain warranty (car has 64k not 62k). It looks like a real PITA to change the water pump....

Anybody done this before and are there any tips to make it easier? I'll obviously do the timing belt at the same time.

Reply to
Charlie

I considered this writeup really good but there is a really good one on vwvortex.com under 2.0l with pictures. do a search using "timing"

Good luck: A4 (MKIV) How to change a timing belt, timing belt tensioner, water pump and accessory belt. The engine is for an AVH, 2001 Jetta GLS, automatic. The AVH succeeded the AEG for a short while, then the AZG was produced. I believe most of the differences are tied to emissions but I can't be sure. All the parts were ordered from Germanautoparts.com. They are helpful and knowledgeable. I'm sure there are others who are as helpful but they really have been great. I'm not responsible for anything that goes wrong. If you're like me, take a digital camera and take plenty of photos just in case you need to see how things come off. Also, use the note book to write down the steps taken in removal, it's a nice checklist for reinstallation. I'm sure there are better ways to do this but this worked for me. This may be too detailed and simplistic for many of you BUT I had never done this before, all went well and the engine is now very, very quiet. This took about 8 hours, including 4 hours of my helpers time. I doubt if we could do it in less than 6, we're very slow. ALL the bolts and screws came out easily, including the famed water pump bolts.

Tools required: Ratcheting torque wrench up to 75 ft-lbs.

6 jackstands, 2 are screw types 1 hydraulic jack Set of hex bit sockets 4 to 10 mm, 3/8" drive Small and medium ratchets Sockets (mm) 3/8" drive, up to about 20mm Small socket extension, 3/8" to 3/8" (this is about the length of a standard 3/8" any mm socket), you'll need to do a bolt removal, neither a deep socket nor a small extension would work Strap wrench 1" diameter 3' long cheater bar for engine mount bolts Screwdrivers, flashlight Small automotive mirror Nail polish, white 2 pages of mailing labels notepad, pen oil pan Materials: About 1 quart of antifreeze and 1 quart of distilled water, to make 50/50 mix. 1 timing belt 1 timing belt tensioner 1 water pump 1 accessory belt (ribbed belt) 1 each 9" long 2x4 1 each 4" long 2x4 2 each mount to body bolts 2 each mount to engine bracket bolts Note, I got these from the dealer, they were about $10.00. They had to be ordered and when I asked why they didn't have any, the parts man said the mechanics just reused the old ones. This is not what the Bentley or Haynes says to do. Both state clearly to replace with new bolts. Haynes Repair Manual and Bentley Service Manual. You'll need one of these for the proper torque requirements. Also, I'm a poor mechanic and both these manuals were used during this. Make sure you have a helper to remove and reinstall the passenger engine mount bracket and the passenger engine mount. It's also a lot easier if you have help to install the timing belt tensioner and the timing belt. Check this forum (VWVORTEX) for postings from Spitpilot, he explains clearly how to mark and match, you don't need to find TDC. He's right, dead nuts on!!!! Do a search of this forum under timing belt to check for other tips. To start: The Bentley implies the engine and transmission have to be lifted from above. This is not necessary.

I used the address labels to mark each piece and fastener as to where it came from and put them all in a cardboard box. Remove the upper engine cover. Take out the oil dip stick, loosen the small bolt at the rear and pull the engine cover forward. Put it aside and replace the oil dipstick. Remove the ribbed belt and it's tensioner. The tensioner has a notch that sticks out on the top of it and you can use a 15mm open end wrench to rotate it to "slack". Just stand in front of the car, fit the wrench and pull it forward. Keeping it like that, remove the ribbed belt, then release the tensioner. Then remove the tensioner, 13mm socket, three bolts. Remove the upper toothed belt guard. There are two clips one to the front and one in back, they are metal and pop off but stay attached to the cover. It's not easy getting the cover off, I removed a vapor line that is to the rear and passenger side of the engine. Not knowing what it was (I assumed it was a fuel line but I think it was a vapor line), I removed the gas cap and fuse 28, which is located on the drivers side panel, which is what you're supposed to do if you're removing fuel lines. Put the gas cap back on right after the vapor line is removed. Loosen bolts on front passenger tire. Block the rear wheels to the rear of the car. Jack up car in front, use two jackstands per side. Jack it up a good distance as you'll have to slide a jackstand and two by four under the engine and transmission. Place the hydraulic jack under the engine with the 9" 2x4 the length of the lowest part of the oil pan "protector". Jack it up 1/16" and slide a jackstand under the

2x4. Do the same with the 4" long 2x4 for the transmission. Put the hydraulic jack off center so the jack screws will support both. When it's jacked up and the load it taken off of the engine mount, rock the car to make sure it's steady. Remove left front tire. You'll have to remove two sound absorbers, one to the front has 4 screws, 25 Torx and the passenger side wheel well one has two screw off fasteners and one Torx. They will slide out easy. For the windshield washer reservoir, coolant reservoir and power steering reservoir, you do not have to remove any lines but the reservoirs have to be moved out of the way, per the below. Unbolt the wind shield washer reservoir, there are two plastic fasteners, make sure you lift the reservoir OFF of the screws as you'll have to move it to the front car to get the engine mount bracket out. Unscrew the coolant reservoir, there are two screws. Unscrew the power steering reservoir, there is one bolt holding it. On the top of the bolt is a plastic holder for some wires. You can flip this off with a screwdriver. Remove the right side engine mount bracket from the body. There are 4 bolts and you'll need the cheater bar. There are two sizes and I marked each bolt and the mount where the bolt went in with nail polish. The bolts were marked with one mark up to four marks. It was easy to figure which new one went where. You'll also have to loosen a bolt on a bracket to the side. You can now remove the engine mount to body bracket. Standing in front of the engine, pull the windshield washer reservoir towards you, move the power steering reservoir off to the right and push the coolant reservoir back towards the passenger compartment. Now while one person holds the lines out of the way, slide the mount to body bracket forward towards you and out. The ribbed belt pulley is mounted on the crankshaft sprocket at the bottom. There are four 6 mm hex bolts and at the center is the crankshaft sprocket. The 4 hex bolts have to be removed. You do not need to remove the crankshaft sprocket. Counter hold the sprocket in the center with the strap belt and remove the 4 bolts. I used a 21 mm socket but should have used the strap belt to prevent damage to the teeth of the sprocket. Remove the center and lower sections of the timing belt guard. There are three bolts that hold the center section. Two of these also hold the lower section. Now use "mark and match". Facing the car from the front, there are 4 things the timing belt runs over. The top one is the cam shaft sprocket, the one lower and towards you is the water pump sprocket, the smooth pulley towards the passenger compartment is the timing belt tensioner and the lowest one is the crankshaft sprocket. I marked 4 times with nail polish both on the timing belt and sprocket on the top (camshaft sprocket) and 5 times on the timing belt and sprocket (crankshaft sprocket) on the bottom. Let the nail polish dry properly. Now, the engine mount to the engine must be removed. There are three bolts that hold it, one can be seen from the bottom, the other can be seen above it and the third cannot be seen but can be felt from the top in a "hole" where the mount to body was. These three bolts are horizontal and "feed' from the passenger to driver side. The Bentley says the bolts must stay in for removal but we took them out, it was easier. The mount comes out through the top. Others have posted to where they have had to move the engine up and down but through patience and manipulation, we got it out, 5 minutes. Someone has to hold the lines out of the way while the other person manipulates the mount. It's pretty big and is somewhat triangular in shape. To remove the timing belt, you have to remove the tensioner. First, look at it. On the back and top are three things sticking up. One is a tab and is bent over. This part fits into a depression in the block about the size of a nickel. Of the other two, one has a point and the other has a "v". If you push the two outside parts together, they move and you can line up the arrow in the center of the "V". When it's bolted on the engine, this should be their final position. Before removing the timing belt tensioner, take a look at how it's lined up and how it will fit. With the tensioner off, the old timing belt will come right off. Be careful not to brush or remove the nail polish marks. You'll need this belt when you "mark and match". Make note of the two small holes on the face of the tensioner. You can use Craftsman bent pliers, Number 45655 by putting the thines into these two holes and rotating it to cause tension. Note it takes little effort to rotate the timing belt tensioner. Remove the water pump. Put a bucket under the car to catch the coolant. Make note of the water pumps orientation as it is installed. There are bolts to the cooling pump and over one of these is the "rear timing belt guard". These use a 13m socket. It's stuck in a tight fit but it will pull out. The removals are now complete. Install the new water pump, to include the rear timing belt guard. Remember how it came off, we messed this up the first time. Now, as a precaution, I counted all the teeth on the new and old belt to make sure the number of teeth were the same. We also counted the marks between each of the nail polish marks to make sure they were the same for old and new belt. It helps having an extra set of hands to transfer the marks from the old belt to the new. Let the nail polish dry properly. Now, from above match the upper sprocket marks to the timing belt and have your partner match the lower ones from underneath. Put the belt on the sprockets about =BC of the way, matching the marks. Hold the belt to sprocket for the cam and crankshaft sprockets, all you have to do is press down on the belt where the water pump sprocket is and the belt should slip into the water pump sprocket. Hold these positions and now slip the belt completely on the tensioner pulley, while the pulley has yet to be installed. After that , slip the tensioner pulley with belt over the bolt that holds the tensioner pulley to the block. Remember the bent tab. Slide the belt completely onto the three other sprockets. Tighten slightly the bolt on the tensioner pulley. Make sure the bent over tab is at the top and slips into the depression of the engine. Using the mirror, rotate the tension with the pliers so the arrow matches the "v". Now tighten to the proper torque. Check each of the nail polish marks to make sure they are lined up. Installation is in reverse order. Make sure when tightening the ribbed belt pulley on the bottom that the marks still line up. Take jacks out of the way. Now turn the motor by clicking the switch just to start but don't start it. Do this 4 or 5 times. You'll have to remove and reinsert the key after two tries because it wont start to turn unless you do that. The purpose of this is to turn the belt so it seats properly. Make sure you add =BD distilled water and =BD coolant. Mistakes we made: Put the bent lip of the tensioner in the wrong place. As the tensioner fits against the block, it's at about 12 o'clock. Forgot to put the lower timing belt guard on properly. Forgot to use strap wrench on crankshaft sprocket, used a 21 mm socket. The reason for the strap wrench is to prevent damage to the sprocket so it doesn't cut the timing belt later. We buttoned up everything and lowered the car to the ground before we tested it. But we were positive we had it right.=20 Good luck.
Reply to
Diarmud387

Thank you!!! That's exactly what I was looking for! Between the two of them I should be able to get it done!

Thanks again!

Reply to
Charlie

Just to let ya'll know, I sucessfully changed the water pump, timing belt, idler and serp belt as well as the thermostat.

The most difficult parts were getting the triangle shaped motor mount out/in because VW in their infinite wisdom loves to put bends in the A/C lines, right over the points where you need to maneuver things. I had to jack up and down the motor to get the mount to wiggle out.

Also beware that the A4 Jetta uses special power steering fluid, along with special G12 coolant.

A major turn off with this car IMHO is the weird fluids it uses that you can only get, for the most part from VW. IOW the 7-1l ain't gonna have it.

The new timing belt (aftermarket) was quite a tight fit but with patience and a little wiggling I managed to get it on without moving the cam or crank sprocket (they were both marked using the "mark and match method, and were also at TDC via the marks as a second check).

FWIW the OEM water pump impeller had literally fallen off the knurled shaft. It appears to be a press on fit which IMHO is ludicrous for cars like this as well as $40,000 Audi A4 that use the same pump.

The new pump (Graf aftermarket) has a steel impeller. I took my time, especially marking the stuff, took digital pics and overall it took a day and a half of working very slowly.

It's mostly dogwork, but you do need an assortment of extensions and different size (thickness and physical size, thin wall, deep etc) sockets because there always seems to be something in the way of the bolts you want to get to and one extension is too long, the other too short, the socket too deep, shallow, the ratchet to thick/long to fit etc.

I think I used every wobble bar, extension, universal etc in my tool crib to make things fit. The problem isn't the sizes of the tools (ie:13mm, 10mm etc) but the length/thickness etc because clearance is very tight.

Take care and thanks for the help!

Reply to
Charlie

I am having the exact same problem with my 2003 jetta, i have tested the thermostat and it works fine. did you have any luck with changing the water pump, or have you found any other solutions to this problem.

Reply to
nesral

I am having the exact same problem with my 2003 jetta, i have tested the thermostat and it works fine. did you have any luck with changing the water pump, or have you found any other solutions to this problem.

Reply to
nesral

So if the water pump impeller is bad would you not get any heat inside the car? Does the radiator get hot?

Reply to
dave AKA vwdoc1
  1. Fan does work and will come on at 190 degrees or a little higher.

  1. Top radiator hose gets hot to the touch.

  2. Bottom radiator hose is COLD..

  1. I also get no heat.

Reply to
nesral

Which engine? Did you look at the trunk lid and see a 1.8t? I vote you examine the water pump and if bad change that and the thermostat. More thoughts within!

hmmm so the radiator fan does come on? Maybe the engine is getting hot enough to cause the radiator fan to come on without the radiator getting hot enough.

My thoughts: No flow through radiator caused by either

*** defective thermostat or *** non-functioning water pump or there is *** a heavy clog blocking the coolant flow! A defective oil cooler could allow oil into the coolant system and that might clog up the system. Now that is an UGLY thought but I can't think of too many other things that could cause it.

What does the coolant look like? Nice pinkish color or brownish?

Reply to
dave AKA vwdoc1

Read my other post in the other thread.... The PLASTIC impeller fails in one of two ways:

  1. It loosens up and slips on the shaft. It is only pressed on which is crap engineering at it's finest.
  2. It breaks into a 100 pieces because the plastic becomes brittle and makes a mess of things.

Either way, the pump, like most things in the typical VW car, is buried and a real PITA to replace on a 2.0l motor. I just did one a couple of months ago and it's not fun.

Go to the Vortex forums for tutorials on how to do this.

Reply to
Stefani Bowers

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