How to clean out the tdi intercooler - Copied from TDi Club
The following applies to a '99 New Beetle TDI, but others should be similar.
You will need a pair of channel-lock pliers or something similar, a large 19-oz can of spray-type carburetor cleaner, a small container into which you will drain the gunk from your intercooler, an empty plastic jug (about 1 gallon size), and some mild detergent (dishwashing soap works well).
1. Make sure the engine is cool, so you don't blow yourself up. You'll need to remove the intake tubing on top of the engine from the elbow just behind the front grill back to the EGR valve. Remove the top engine cover if necessary.
2. Using the pliers, loosen the hose clamps securing the joints of the horizontal part of the intake tract on top of the engine, and move them away from the joints. You need to remove the plastic piece of tubing, together with the rubber elbows which attach it to the rest of the system. Don't try to remove the piece with the EGR valve! It's too hard to do, and there's no need.
3. Once you have removed that plastic piece along with the elbows, spray some carburator cleaner into the section of pipe you removed to clean out the oil and gunk. Let it drain into your drain bucket. Set it aside to dry. You can also spray a small amount of carburator cleaning into the open end of the hose toward the EGR valve, and wipe out the inside of the hose with a rag. Be careful not to spray too much cleaner in there! You don't want to blow up your car when you start the engine!
4. Underneath the car you should be able to easily locate the intercooler. There will be what appears to be a radiator hose attached to it. MAKE SURE IT'S THE INTERCOOLER AND NOT THE RADIATOR!!! Otherwise you'll have a big mess all over your driveway. There is a short piece of rubber tubing attached to the intercooler with a hose clamp, and a plastic hose running back to the turbo from the other end of the rubber piece. Slide both hose clamps off the rubber connector and back onto the plastic hose. Remove the rubber piece and clean it out, then set it aside. Spray a little carburator cleaner into the plastic hose towards the turbo, but not too much! Wipe out the end of the plastic hose with a rag.
5. Set the drain bucket under the intercooler so that the cleaning solvent and oil will drain into it. Working from the top, spray the entire remaining amount of carburator cleaner into the top of the intercooler outlet hose. Go CRAZY! Just let it run. You could even seal off the intercooler down below and fill the thing up with solvent and let it sit there and work for a few minutes, if you want to. Eventually you'll run out of spray. (It'll take a while.) By the end there was nothing but clean solvent running out the bottom!
6. Now you have to flush out all that solvent and it's related fumes from the intercooler so your car doesn't explode when you start it. You may want to put a bigger drain bucket under there if you don't want a whole load of dirty water and soap bubbles running down your driveway. Squirt a small amount of dishwashing soap into the empty gallon jug and fill it with water. Working quickly, pour the entire contents into the top of the intercooler outlet hose and let it drain down through the intercooler. Once that is done, rinse out the jug thoroughly and follow your soapy water enema with TWO gallons of clean water. (You probably don't want soap bubbles spewing out your tailpipe, do you?)
7. Take care to let all the water drain out through the bottom of the intercooler. Due to the angle of the fitting at the bottom, some water might be pooled up in there. You can remove most of it by stuffing a clean rag into the inlet fitting and letting it soak up the water. Fit the bottom pipe and rubber connector back together, and replace the hose clamps. Put the upper intake tract back together, too. Make sure all the hose clamps you removed are returned to their places!
8. Start the car, and let it idle for 15 minutes. That will allow time for it to warm up thoroughly and evaporate most of the residual water in the system. Don't rev the engine during this time, in order to avoid forcing liquid water into the engine!
9. Go for a drive and enjoy a new-found sense of peace and satisfaction!
This procedure was not researched by me and nor do I accept any responsibility if you use this information.
Disclaimer
This information is provided by other owners based on their experiences and knowledge. I can offer no guarantees or warranty nor endorse any changes or repairs you make to your car based on the information given here. Everything you do is entirely at your own risk. You should not undertake anything contained within these pages if your are neither confident or competent and do not have the right tools to do so.
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This information is provided by me to assist owners in modifying and repairing their car, all content belongs to me unless otherwise indicated and the owner of that content has given permission for it to be used. You are permitted to read this content but are not allowed to copy any part of it without first contacting me directly.
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