98 s70 glt, really odd noise, not air pump

terratek · Post by **terratek** » 07 Dec 2011, 16:04

I have had a few volvos, and this problem is a new one for me..

A few days back we finally had some rain here in san antonio. I misjudged the depth of some standing water and ran through it at around 20mph. Loads of steam, etc..

Now a few days later there is a sound like an exhaust leak, but it is independent of rpm. The noise starts between half a minute and 2 minutes after starting the vehicle, and it seems to be coming from either the exhaust heat shield area or the passenger side front of the vehicle.

I will try to grab a video and youtube it.

Any ideas what it could be? I figure the engine is pretty much ruled out as it is not dependent on rpm, transmission is ruled out as it is on the drivers side and the noise happens no matter what gear i am in. I would rule out the turbo, but this is my first turbo vehicle, so no clue.. and I would rule out exhaust except it sounds like it is coming from that area.

Check engine light is not on, but tried to pull codes anyway. 3 codes pulled: p1308, p0442, p0455. None of which should be causing any issue like this (as far as i know).

Any help would be greatly appreciated, will update if i can grab a vid/audio of the issue.

trin

Post by **jblackburn** » 07 Dec 2011, 18:06

The noise starts between half a minute and 2 minutes after starting the vehicle, and it seems to be coming from either the exhaust heat shield area

This makes me think you may have filled the air pump with water.

The air pump is under the battery - you can see it from underneath the car if you remove the splash guide. Take a small drill bit and drill two holes at 5 and 7 o'clock in the pump housing from underneath the car to allow water to drain.

I don't know why holes weren't there in the first place, but that's what ends up killing a lot of them.

Post by **kickin_it** » 07 Dec 2011, 18:13

The codes p0442 and p0455 deal with your EVAP system, not sure why this has not triggered CEL. The p0138 is an error with the oxygen sensor, like the oxygen sensor is registering poor exhaust.

applcor · Post by **applcor** » 07 Dec 2011, 20:19

Sounds to me like somebody previously extinguished the CEL. Does it come on when you turn the switch to the ON position? jblackburn is absolutely right about the water in the pump - that is an easy fix too.

terratek · Post by **terratek** » 08 Dec 2011, 13:38

The car has a few issues, I have slowly been taking care of them as I can afford to.. Replaced the timing belt, tensioner, etc. as there was no record of it having been done and the car had 150k on it when i picked it up. Losing wiper fluid from somewhere (car originally had headlight wipers, which po removed, so maybe there is an unplugged hose somewhere), still need to do the flametrap as it is clogged. Replacing the fuel filter tomorrow during the tire rotation, as there is no history of it being replaced.

applcor: CEL illuminates when key is in on position. I suspected it was bypassed as well, but not exactly sure where the po would have bypassed it to still have it illuminate on start.

kickin-it: I thought p0442, p0455 were evap system, and p1308 was accelerator sensor.

jblackburn: added vids to youtube to confirm the diagnosis, if it's just a matter of drilling a few holes, will get under it tomorrow after i rotate the tires.

Fast to slow noise

slow noise with acceleration to show rpm isn't a factor

terratek · Post by **terratek** » 09 Dec 2011, 14:03

Drilled the holes, pump was dry.

Any other ideas? I need to hit hf on tuesday to pick some stuff up, may pick up a stethoscope and try to actually pin down where the noise is coming from.

terratek · Post by **terratek** » 03 Jun 2013, 22:42

1.5 years later, forgot to update... i finally figured out what the problem was... there is a small diameter hose (looks like vacuum, but who knows) on the passenger side rear that came loose. as soon as it was reconnected, no more noise.. the piece it plugs into has expanded so it now comes loose every 5-10 days, but will be fixed next time the car has some down time.

Post by **abscate** » 04 Jun 2013, 03:09

Sounds like EVAP hose on canister. Glad you got her running well again, and thanks for followup

Post by **jblackburn** » 04 Jun 2013, 06:01

Wow...sorry your topic was overlooked for that long! I'm glad you figured out your noise though. Was it the vacuum hose that connects behind the power steering pump or to the fuel pressure regulator near the steering rack?