Ask Honest John

Honest John Ask Honest John » Why do so many cars struggle with water leaks?
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks

Why do so many cars struggle with water leaks?

I'm trying to avoid buying a used car with bad reputation for water ingress. I don't want to paddle again, like with my last motor. Lately, it seems too many brands and models have this issue when looking at the owner reviews and it's narrowing my choice a lot. There must be water-tight, used cars out there, which are inexpensive models. Any knowledge of which ones are best?

Asked on 19 June 2020 by BK

Answered by Dan Powell
Water ingress is usually caused by the bulkhead drainage vents becoming blocked with road dirt or old leaves. All cars are susceptible to this if the owner doesn't clean it regularly or parks it under trees for long periods.
Similar questions
You've said that cars struggle with water leaks because the bulkhead drainage vents get blocked, but how do I find the vents to prevent this happening? The manual does not say.
I bought a Vauxhall Astra from my local dealer 12 months ago. I have taken it back to the garage three times over water leaks. The main problem is the rear doors, with water getting into the door panels....
I have a 2010 Mercedes-Benz SLK 200, which I bought last year for some much-needed fun after the first pandemic lockdown. Recently, I have noticed a large amount of water in the boot (spare wheel well)...