Black streaks on bodywork and washer jets

[david924s]

I have an issue with my white car, I can wash it polish until it is gleaming and clean then the first sign of rain I get black streaks down the bodywork doors, rear and front wings. It appears to be coming from the seam line that runs the length of the bodywork, before I start cleaning out under the seam can someone tell me are the black streak likely to be caused by a breakdown of sealant or just a build up of dirt in the joint? I obviously don't want to clean it out if it supposed to be sealing the two edges.

Next issue is with the washer nozzles, does anyone else have a problem that they squirt water out when going down hill or braking hard? Mine do it seems as though when the fluid from the boot reservoir is higher than the bonnet the fluid comes out of the nozzles without activating the washers. More of a nuisance really especially when you have just cleaned the car as it leave washer fluid across the bonnet and windscreen. From what I can see under the bonnet the line comes from the reservoir and splits into two for each nozzle, no non return valve but then that would only keep the fluid up to the nozzle and not prevent leakage under gravity.

[John_W]

The washer jets issue is well known: see e.g. HERE for the solution.

As to the black streaks, what is the composition? Just road dirt from the wheel arches which is easily washed off, or something organic based which needs a solvent to remove?

[david924s]

The washer jets issue is well known: see e.g. HERE for the solution.

As to the black streaks, what is the composition? Just road dirt from the wheel arches which is easily washed off, or something organic based which needs a solvent to remove?

Thanks for the reply about washers I will take a look and see what can be done for that problem.
Black streaks, they will wash off with soap and water easily so would suspect just a build up of dirt in the seam leaching out when rained on my concern was is it seam sealant in which case I don't want to pick it out for obvious reasons. it happens down both sides of the car on both doors and rear wings under the bodyline seams, not so much on the front wings but also on the front bumper again underneath where the pieces fit together it will happen almost as soon as the car gets slightly wet so not necessarily heavy rain.

[John_W]

Not sure what causes that. I occasionally get mud leaking from the front wing horizontal joint if I’ve been out in vile conditions (so not often).

[HJ2]

I love the new avatar

[Saltire]

I love the new avatar

Although I’m surprised John lets his Birmingham screwdrivers get in that condition - I thought Scots looked after their toolboxes

[Dave Eds]

Sounds like colour running out of the hood fabric. What has it been treated with?

[david924s]

Thanks for the replies,
It certainly isn't road dirt as the car had not moved the last time it happened, I had cleaned them off with waterless polish so all cleaned away then slight rain shower few seconds and they appeared as like magic so it seems to be something in the seam leaching out but not sure what, it is on the bodywork below the midline seam so not from the hood the car above stays clean and it has a cover over the hood so it stays dry as well.

[Rambo]

Sounds like colour running out of the hood fabric. What has it been treated with?

Exactly my thoughts Dave.

Have you recently treated the hood canvas with black Renovo and been a bit over exuberant ? If so, that's the problem and petrol on a rag should clear it

PS the black streaks even show up on my Black Beastie where I was overly enthusiastic round about the A pillar

[david924s]

Did treat the hood a few weeks ago but the black streaks are not at the top of the car but only from the top swage line downwards above them the car stays white, it also has a rain cover on the hood and top section so no chance of that getting wet.

I had thought it was coming from the body joint section where the top and bottom sections meet but it is more pronounced on the doors and I don't think the door skins are in two pieces joined but one piece with a swage line to match the bodywork. Also get the same black streaks on the front bumper and again that seems to be coming from the seam line above the indicator pods. Will try to get a good look at the weekend and see what is inside the joint areas.

[Rambo]

David - can you post some photo's for us to see please. We might be able to shed some more light on your problem.

My money is still on the fabric conditioner, particularly as you have just treated the canvas. And don't forget, your cover or cape may not be completely waterproof and it might just wick some of the black stuff (Renovo ???) further down the body

If you think it is coming from the seams I would suggest blasting it with a garden hose and spray. Maybe even a quick blast with a Karcher high pressure spray ???

PS I had a similar problem with incontinent washer jets about 15 years ago and spliced in the non return valve just under the bonnet, as JohnW mentions in his link. Easy job and problem solved. No more embarassing dribbles !!

[david924s]

David - can you post some photo's for us to see please. We might be able to shed some more light on your problem.

My money is still on the fabric conditioner, particularly as you have just treated the canvas. And don't forget, your cover or cape may not be completely waterproof and it might just wick some of the black stuff (Renovo ???) further down the body

If you think it is coming from the seams I would suggest blasting it with a garden hose and spray. Maybe even a quick blast with a Karcher high pressure spray ???

PS I had a similar problem with incontinent washer jets about 15 years ago and spliced in the non return valve just under the bonnet, as JohnW mentions in his link. Easy job and problem solved. No more embarassing dribbles !!

The washer jets I will fit a non return valve under the bonnet as suggested at the weekend, for the black streaks I can say for definite it is not from the hood apart from the hood remaining dry under the cover (it is waterproof) the black streaks only appear from under the swage line and nothing above them so definitely not running down form the hood area, I get similar marks on the front bumper and front wings both well away from the hood area.

Like I said I thought it might be from the body seam but I don't think the door skin has a joint only a decorative crease to match the top and bottom clamshell joints.
Picture below not the best but this was after cleaning them off and a shower of about 1 minute so not heavy rain and with the cover in place throughout.

[Jamie N]

David, maybe its years of rubber dust thats built up where my feather duster didnt reach , mind that car never went out in the rain so you never know!.

I know you are adamant its not the renovo, but the swage line on the door has no join where dirt could lurk and run out from, so it surely has to come
from above?, maybe the upper surfaces have a better coating of wax which is repelling any residue and its sticking to the lower parts because its not
so heavily waxed?.

Anyway, i had a yellow mini convertible here 2 weeks ago to get work done and part of that was doing the hood with Renovo, i left the car outside
that night because the forecast was good, but it actually rained during the night, when i saw the car in the morning i was horrified to see it
completely covered in black streaks , thankfully as you say it washes off easily enough, but 2 weeks on the owner tells me its still showing a bit, not just after rain but early morning condensation running down. It does seem to be a known issue, plenty people reporting it if you
look in Google, much more more noticeable on a white car though, owners of black or very dark cars might not be aware even it was heavily streaked.

Also , have a look at other light coloured cars in the area, maybe something to with the Smoggies?.

[david924s]

David, maybe its years of rubber dust thats built up where my feather duster didnt reach , mind that car never went out in the rain so you never know!.

I know you are adamant its not the renovo, but the swage line on the door has no join where dirt could lurk and run out from, so it surely has to come
from above?, maybe the upper surfaces have a better coating of wax which is repelling any residue and its sticking to the lower parts because its not
so heavily waxed?.

Anyway, i had a yellow mini convertible here 2 weeks ago to get work done and part of that was doing the hood with Renovo, i left the car outside
that night because the forecast was good, but it actually rained during the night, when i saw the car in the morning i was horrified to see it
completely covered in black streaks , thankfully as you say it washes off easily enough, but 2 weeks on the owner tells me its still showing a bit, not just after rain but early morning condensation running down. It does seem to be a known issue, plenty people reporting it if you
look in Google, much more more noticeable on a white car though, owners of black or very dark cars might not be aware even it was heavily streaked.

Also , have a look at other light coloured cars in the area, maybe something to with the Smoggies?.

I do know it isn't the hood or renovo as like I said it doesn't get wet and actually did the same prior to re-coloring the hood.

Just annoying as it only seems to happen on the lower part of the car below the swage line and as you say the door seam is not a joint so that isn't holding dirt.

Not part of living here as I have a white motorhome and that definitely gets wetter and doesn't exhibit the same problems.

[Rambo]

It's probably all the pollution from Rawshyte and Grungemouth coming out Jamie:. All trapped in those rubber seals

[Jamie N]

You never know Mark, its certainly being spewed out every minute of every day, but then again surely the really heavy pollution places like London would have cars looking like Zebras!.

[david924s]

It's probably all the pollution from Rawshyte and Grungemouth coming out Jamie:. All trapped in those rubber seals

Problem with the rubber seal theory is they are not getting wet either as under cover the streaks appear purely on the lower half of the car almost as if the seam in the door has muck in it which it doesn't, anyway if I get the chance I will wash it at the weekend and get a brush into all the gaps to see what comes out then see how it goes.