P38 damp in passenger footwell

Slight trace of damp in the passenger footwell of my P38...OK we had 52mm if rain in one morning so I suppose that is not too bad, but even so...
The horizontal panel under the glovebox had a trace of damp in the middle at the front (ie engine side).
So that is under the lower edge of the windscreen about a quarter of the way from the left side.
It isn't the sunroof as I haven't got one.
It isn't the air-con condensate as the air-con has been totally defunct for some time.
The pollen filters are dry as a bone.
Presumably the plenum chamber has a drain, which may have filled with debris as often happens?
But I can't find any drain to clean out - any info on how to clean that drain (or any other relevant info) would be very gratefully received.

Is the driver's side dry?

Pollen filter covers.

+1

+2

Bit of sealant on screw heads and some of that draight exclusion strip as a bead work well. Unless they are cracked

The screws around the windscreen can rot out and start to let water by.

Very useful tips - many thanks.
The driver's footwell is dry.
The pollen filter covers are not cracked and they fit well. The pollen filters themselves are bone dry and there is no sign of leakage past the cover seals.
I'll remove the horizontal trim below the glove box and see if I can work out where the drip is coming from.
We are due to get a good downpour this afternoon and I'll be out there with my torch!
Don't know if it is relevant, but the engine seems to get very wet and the under-bonnet insulation is wet. Maybe the washer jets are not properly sealed, or perhaps the pipes to them are perished.

P38 Monkey said:

Very useful tips - many thanks.
The driver's footwell is dry.
The pollen filter covers are not cracked and they fit well. The pollen filters themselves are bone dry and there is no sign of leakage past the cover seals.
I'll remove the horizontal trim below the glove box and see if I can work out where the drip is coming from.
We are due to get a good downpour this afternoon and I'll be out there with my torch!
Don't know if it is relevant, but the engine seems to get very wet and the under-bonnet insulation is wet. Maybe the washer jets are not properly sealed, or perhaps the pipes to them are perished.

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That does sound like washer jets. Cannot see that making it through the bulkhead though.

Heater matrix is another option for the leak in the car. Bit of hassle to replace.

There’s an aircon drain gets blocked. Just needs clean out.
Wouldn’t be dependant on weather though same as washers.

Is there any smell in footwell of screenwash/coolant?

If it tastes sweet then is probably coolant

So, in preparation for the rain test as promised by the Met Office (yellow warning of heavy rain) I removed the trim panel, pulled back the carpet and put newspaper as a marker under the passenger side. Stair-rods to the East, cats-and-dogs to the West, siling down in the North, and we had about 3 raindrops, all of which missed. Undeterred, I washed the car with a hose this morning and directed lots of water down the windscreen grille. Not a drop inside. So perhaps the small amount of condensation on the rubber underside of the mat was the result of a long sea voyage from Japan and several months outdoor storage prior to receipt. Anyway, it is good to know the detail listed above. The P38 is into the garage for pressure testing and refilling of the air-con system tomorrow, so I'll get them to pop it up onto a ramp and make sure the drains (either side of the gearbox??) are clear. The water onto the engine is from around the washer jets housings, which do not seem to have any sealing washers between them and the bonnet, to be investigated. Once again, the postings above are greatly appreciated - many thanks as ever.

The washer jet housings are loose and let water in to drip on the engine - not good. Two different hose connections (one 6mm, one 5mm, and the 6mm one has a split hose unsurprisingly) but the housings themselves look the same. Any info on how to tighten them would be very useful....

RangeRoller dt said:

There’s an aircon drain gets blocked. Just needs clean out.
Wouldn’t be dependant on weather though same as washers.

Is there any smell in footwell of screenwash/coolant?

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Looks like there isn't a leakage problem, but could you tell me where that air con drain exit is please? Air con service tomorrow and I'll get them to clean it.

The aircon drains are up in the transmission tunnel ether side of the gearbox, its normally a of job of lay under the motor arm up in the tunnel give the teat a squeeze and get an arm full of water

Hmmmm - the washer jet housings seem to have changed in 1997 or so - my VIN indicates the earlier type (AMR5257). My P38 seems to have one earlier type and one later type (which is a loose fit and leaking rainwater). Looks like that answers the problem - I'll get an earlier type and fit new pipework too. Getting to know my "new" P38 day by day, one micro-project at a time.

New pollen filters to fit.
I would usually clean out the scuttle drains and HVAC intake plenum drain, but where are they on a P38?
I believe the scuttle drains are in the expected place at each end of the scuttle, but that places them under the pollen filter housings.
Is that correct?
If so, any tips on removing the filter housings?
And where is the plenum chamber drain?
As ever, any tips and advice very gratefully received....

P38 Monkey said:

New pollen filters to fit.
I would usually clean out the scuttle drains and HVAC intake plenum drain, but where are they on a P38?
I believe the scuttle drains are in the expected place at each end of the scuttle, but that places them under the pollen filter housings.
Is that correct?
If so, any tips on removing the filter housings?
And where is the plenum chamber drain?
As ever, any tips and advice very gratefully received....

Click to expand...

Is the foam intact on the air intake under the windscreen? If it's intact, it's unlikely the plenum drains are blocked. However if the foam has failed, you need to remove the vertical windscreen side pieces, screws under the door rubbers. Using pliers with a piece of rag to protect the trim, the lower windscreen trim can then be slid out with a bit of a heave leaving all the plastic mounts in place, they can then be removed without breaking and refitted to the trim ready for refitting it. Then it's just a case of removing all the screws to remove the scuttle. The drains are at each end of the plenum. silicone all screw threads and heads when refitting.
If the foam needs replacement, I use perforated metal which will last for ever, photos & details on request.

Datatek said:

Is the foam intact on the air intake under the windscreen? If it's intact, it's unlikely the plenum drains are blocked. However if the foam has failed, you need to remove the vertical windscreen side pieces, screws under the door rubbers. Using pliers with a piece of rag to protect the trim, the lower windscreen trim can then be slid out with a bit of a heave leaving all the plastic mounts in place, they can then be removed without breaking and refitted to the trim ready for refitting it. Then it's just a case of removing all the screws to remove the scuttle. The drains are at each end of the plenum. silicone all screw threads and heads when refitting.
If the foam needs replacement, I use perforated metal which will last for ever, photos & details on request.

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That's really helpful - thanks. The workshop manual diagram says that there is no central air intake but an individual intake for each pollen filter - I need to check that out. Very likely that the foam has failed and I have read the other postings on that / perforated metal etc. Photos and details would be appreciated - are they in some posting in the Forum? Or can you PM me?
Yep, I need to get that trim off and have a look underneath. Critically important to have the method though, so that info is really appreciated...thanks again.

P38 Monkey said:

That's really helpful - thanks. The workshop manual diagram says that there is no central air intake but an individual intake for each pollen filter - I need to check that out. Very likely that the foam has failed and I have read the other postings on that / perforated metal etc. Photos and details would be appreciated - are they in some posting in the Forum? Or can you PM me?
Yep, I need to get that trim off and have a look underneath. Critically important to have the method though, so that info is really appreciated...thanks again.

Click to expand...

PM me with an email address and I will send you details, it's easier than going via LZ.

Nightmare job mate try not to damage the little white clips there no longer available I did mine a few years ago most of the screw heads under the trim just broke when turning them so much rust and as data says when replacing put a small bit of silicone on each screw