Passat 1.9tdi fuel filter

**Alby43** · 09-01-2009,08:13 PM

The plastic engine cover on my 2001 1.9tdi (130) passat has chaffed through the fuel filter 'manifold' (the black unit on top of the fuel filter which four of the six fuel hoses connect to). On pricing a new unit at my local vw dealer I was informed that I would have to purchase all three parts (canister and the two units the hoses connect to) at a price of £160.
Apparently the slightly later models had a redesigned one piece fuel filter with the hose connections being part of it.
My question is, with a bit of replumbing, can I fit the later (considerably cheaper) filter to my car?

**Crasher** · 09-01-2009,08:30 PM

That is the fuel cooler and to change to the later system you would have to convert to the later fuel cooler which would be involved and costly.

**mance7** · 09-01-2009,11:52 PM

hi alby43
yes you can change it over i must have done the best part of ten .... its very easy .....
everyone told me change this that and the other but you dont need to?????

**Col** · 10-01-2009,12:12 AM

Do the later B5.5's even have a fuel cooler ?

I'm sure mine doesn't.

I'd assume if it did it would be the same as those fitted to PD engined MK4 Golfs i.e. horizontal rad fitted to the floorpan ?

Never seen a cooler underneath on my Passat.

**Crasher** · 10-01-2009,12:13 AM

And so deleting the fuel cooler. What are you going to do when these ten come back with damaged fuel pumps and fuel tanks? The fuel cooler is there for a reason, not just to look pretty behind the right hand bumper grill. VAG do not fit parts for no reason, the fuel cooler is there to reduce the temperature of the fuel returning to the tank as it is so hot it can damage the tank and its components.

**Col** · 10-01-2009,12:15 AM

Originally Posted by Crasher

And so deleting the fuel cooler. What are you going to do when these ten come back with damaged fuel pumps and fuel tanks? The fuel cooler is there for a reason, not just to look pretty behind the right hand bumper grill. VAG do not fit parts for no reason, the fuel cooler is there to reduce the temperature of the fuel returning to the tank as it is so hot it can damage the tank and its components.

Crasher, see above.

Do the later 5.5's have a cooler?

I'm not sure they do, I've never noticed one on mine ?

**Crasher** · 10-01-2009,12:20 AM

Yes, it is fitted to the floor along the side of the fuel lines on the right hand side. It has a louvered metal cover over it, goes by the part number 3B0 203 492 A and costs £125. I have had to replace a few after numpty tyre fitters have squashed them with trolley jacks.

**hongkongstuey** · 10-01-2009,12:39 AM

how hot does the fuel get before returning to the tank? just wondering, if it hasn't been burnt?

**Alby43** · 10-01-2009,12:40 AM

Ok. Thanks for the advice. I think your right Crasher, they wouldn't fit a cooler for the hell of it. I,ll see if I can try and carry out some sort of repair before I part with my hard earnt cash. Have tried car breakers but I think they are wise to the value of this item.

**Crasher** · 10-01-2009,12:13 PM

Originally Posted by hongkongstuey

how hot does the fuel get before returning to the tank? just wondering, if it hasn't been burnt?

The fuel has been heated up by the tandem pump on the side of the head and then pumped at high pressure into the head to the injectors and then the excess is bled back so it can be well over 100°c, in VAG’s opinion, hot enough to damage the fuel tank itself in certain circumstances plus the sender and lift pump. As the fuel keeps circulating it will get hotter and hotter. Obviously not at this time of the year but in the middle of summer (what’s that anyway?) and a traffic jam, the returning fuel can be extremely hot. As I said, they would not go to the expense of fitting a cooler if it wasn’t required. The early Passat system was a water cooled design that was quite complex and expensive, from 01/2002 production it was replaced by an under floor cooler. You can see the fuel supply temperature in Measuring Blocks but not the return temperature.