Rough Idle After Heavy Rain

Alwick · Post by **Alwick** » 24 Jul 2012, 12:16

Last week we got a monster storm and my car sat under a heavy stream of water coming off a gutter for about an hour.
A couple days later, on the first start up the car idled really rough, not a surging or dipping idle, more of a very rough vibration.
It smoothed out after 15-20 seconds and drove fine for a few days.
This morning, after another rain, I had the same symptoms on intial start up, but not quite as rough. Again, it went away after time and drove fine. No CEL.
Plugs are new (6 months ago) Volvo. But I don't know when the last time the wires or caps were changed.
Could moisture be affecting the wires and then drying out after I start driving?

Post by **jblackburn** » 24 Jul 2012, 12:21

Could moisture be affecting the wires and then drying out after I start driving?

Yes, definitely - especially if there's not a good rubber seal behind your hood near the windshield. I've done the same to mine when I've sprayed the oil off the engine at a car wash.

Alwick · Post by **Alwick** » 24 Jul 2012, 12:28

You know, it's funny that you mention that, because I opened the hood the other day and the rubber weatherstripping that runs beneath the windsheild at the rear of the engine compartment had popped up. I will check the wires and caps and probably just change them to be on the safe side. What do you think?

Post by **pkc303** » 24 Jul 2012, 12:34

If you don't know the age of the wires, I think changing them, albeit expensive, would be your best bet. The car will run much smoother. I had a similar problem, and that fixed it.

Post by **jblackburn** » 24 Jul 2012, 14:55

+1. And use Bougicord wires, not Bosch, not other aftermarket brands. These cars are incredibly picky about things like that.

KlubMarcus · Post by **KlubMarcus** » 24 Jul 2012, 15:54

jblackburn wrote:+1. And use Bougicord wires, not Bosch, not other aftermarket brands. These cars are incredibly picky about things like that.

Still running Bougicord brand wires myself. They are the OEM supplier for Volvo. See, the French can do something right!

Post by **pkc303** » 25 Jul 2012, 21:58

That's terrific. Good luck. Alwick, please post what your findings are to complete this thread.