prescott

Hi

I have an '88 S4 manual.

I've had the smell of coolant when car was at operating temperature and had to add 1 L of water to the overflow tank 3 weeks ago. I couldn't find the leak at the overflow, or at the radiator hoses.

Took the car into the shop to pin down the coolant smell/leak and they found a small leak under the air intake. The coolant is running forward towards all the belts and they are worried about them slipping. TB/WP was done last year, about 10,000 miles ago. The state they will have to remove the intake manifold to place new gaskets.

I asked them if they should be replacing MAF/flappy and other jobs while they are in there. They said no just fix the leak with new gaskets.

The records show nobody has lifted the intake ever, so they are 26 year old from the factory.

I didn't know we had a coolant hose under there! In your combined experience, what would YOU do if you have to pull of the intake manifold? They are ordering parts, so the job won't be started for 1 to 2 weeks.

Thanks for your help
Brian

Wisconsin Joe

Fuel lines. If they are original too, they should definitely be replaced.
Roger has a couple different options.

daveo90s4

Also knock sensors, hall sensor, idle stabilizer valve, all rubber hoses, the fuel metal line that runs to the front of the engine and attaches to the right hand cam cover (corrodes at the attachment point), all fuel hoses. If you were able to do this yourself then the labour cost saving would easily cover the cost of these parts.

StratfordShark

Well I don't think I'd be removing the intake manifold, and I can't think of any gaskets under that would fix a leak, other than the o-ring/gaskets under coolant bridge that sits in front of the intake (and usually requires intake to be lifted to enable good access to coolant bridge bolts).

Under the air filter housing (is this what you mean by intake?) is the heater valve to block hose on the left side that is a common failure, and also on the right side a bolt holding down fuel damper that goes into water jacket. But this bolt is thread sealed and rarely leaks unless disturbed.

Please can you clarify source of leak? There may just be confusion over terms and your shop are doing the right thing, but my read of your post is ringing alarm bells!

daveo90s4

... and water bridge O-rings (are these the cause of your leak?) and the gasket(s) under the water system connectors atop the block. Oil filler neck rubber gasket too. I don't remember what gasket there is between intake manifold and head. Whatever that is replace that too. Make sure the shop doing the work has a pair of intake blank-off plates to cover the inlets while the manifold is off. These holes 'suck' washers and nuts down even with the engine off! I got mine from Dave Riberts at 928 Specialists.

SteveG

I'd certainly be sure about the heater control valve, the hose to, and the hose from it to heater, before doing anything else. Cheap fix and easy to get to. Also more likely than head.

If the coolant was changed every 2-3 years and it was not abused, it isn't likely to be the head gasket. But you live in a hot climate.

prescott

All the fuel lines were replace last year with Greg Brown's masterpieces.

Calling the shop. Doesn't make sense to me now.

Chalkboss

The intake does not have to come off to remove the water bridge. Done it a few times.

Bertrand Daoust

I would look at the water bridge first.
Like Don said, you can remove it without removing the intake.

https://rennlist.com/forums/928-foru...g-r-and-r.html

Thanks Dwayne.

Also, you should think putting the paper gaskets there too.

https://rennlist.com/forums/928-foru...lly-fixed.html

Good luck.

prescott

Coolant bridge is leaking. That's why they gotta take off the intake manifold.

So, while they are at it, should they replace the knock sensors, the flappy, rotary idle actuator (idle stabilizer), mass air sensor, MAS rubber elbow? Of course the hoses and vacuum lines, 5 way splitter.

Anything else?

How about getting the fuel injectors cleaned while the rails are off?

the flyin' scotsman

given the car is 26yo Id replace everything for peace of mind for another longtime.

the injectors are not recondition when cleaned so Id replace them also.........call Roger for full details of parts required.

prescott

We don't have to remove the intake? That's terrific!

I'll forward Duane's write up to the mechanic!

Thanks guys!