shuddering and surging
 

I have a 2000 S40 w/ about 67,000 miles. A couple of days ago, I was having some fun and decided to really stomp on the gas. I brought it from 0 to about 65 and then braked pretty hard to take a turn. It really took off and everything seemed fine.

Later in the day (after the car had sat for a while) I was entering the highway and when I hit the gas, the engine started surging and shuddering and the check engine light came on. The light went off, but the engine still surged when accelerating.

This morning, the check engine light came on when I started and stayed on. It runs fine when gradually accelerating or maintaining speed. It only surges when I accelerate hard.

Any ideas? All of the normal maintainence stuff is taken care of (plugs, air filter, oil...) so I'm leaning towards a fuel issue or turbo issue. I had the fuel pressure regulator changed about 5 months ago.

FYI: I don't drive that much, only a couple of miles a day. No idea if that makes a difference.

Any help would be great. Thanks.

RE: shuddering and surging
 

Hi cgerdeman,

I had the same thing happen to me (heavy accelerating entering hiway, then engine light came on). Volvo recommended replacing the ignition coils (there are two). But the guy said that it might only be one coil that is bad, so only change one at a time. I bought one (they're ~$50 each on ebay) and replaced it. It got a little better, but still not 100%. Once the other one was replaced, it ran fine.

Hope this helps.

RE: shuddering and surging
 

you might want to try this first, change you plugs......i had the volvo plugs in, i put some after market bosch plugs in and the shuddering and check engine light thing started on me(when acceleratin hard), when i put the volvo plugs in, it was all better...

RE: shuddering and surging
 

Do you mean that the engine revs increased but the speed of the car didn't?

If so, then suspect the clutch if manual transmission & gearbox if auto box. You may have burned something out in terms of clutch/auto box with traffic light grand prix the previous day.

BB
:(

RE: shuddering and surging
 

My Vote is start with the plugs and the coils.

RE: shuddering and surging
 

Thanks everyone for the input. I'll go pick up some plugs and coils and see what happens.

gordon368: I used Bosch plugs too, about 5 months ago. I'll switch back and see what happens. Can I get Volvo plugs anywhere besides the dealer?

Black Beauty14: No, the engine doesn't rev up. It bogs down.

RE: shuddering and surging
 

what ever you do, dont put any after market plugs in, regardless of whether they say they will fit, reason being the tips of the plugs, volvo's tip of the plugs differ from the size and shape of bosch's plugs tips...Its like 30$ for volvo plugs, i reccommend getting the volvo ones strongly if u use the bosch plugs they can and maybe will damage the coils even more..

I can betcha its those awful bosch plugs!!!! let me know what happens when you put the volvo plugs in ...

RE: shuddering and surging
 

I replaced the Bosch plugs with Volvo plugs and it seems like that took care of it. However, the check engine light is still on. Does that need to be reset manually?

I took it out on the highway and gave it some gas and didn't have any shuddering. It seems to run a little better too. The Bosch plugs were pretty ugly (after only about 3000 miles).

Thanks again.

RE: shuddering and surging
 

Someone will need to clear the light with a scanner.

RE: shuddering and surging
 

OK. Thanks again for the help.

RE: shuddering and surging
 

i thought you could clear the check engine light by, holding down the trip with the key ignition in position 1 for 10 seconds, then in position, then in position 3 all the lights on the dash come on, and when the check engine light comes on, you let go of the trip button, and the light resets?.. isnt that how you clear the check engine message?

RE: shuddering and surging
 

Thats how you clear the service light.

RE: shuddering and surging
 

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RE: shuddering and surging
 

Actually I have reset my CEL with the trip button and key trick before and was sucessful. That is what the dealer told me to do. I believe it clears both of them

RE: shuddering and surging
 

NO IT IS ONLY FOR THE SERVICE LIGHT.

RE: shuddering and surging
 

First, dont waste your money buying fancy plugs, boshe will only last 6 to 8 months and you have to pay
like 10 bucks a plug. Best thing to do is get the cheapest coppers and replace then every 3 to 6 months.

I have same problem with mine, boshe plugs were crap and had new ones installed. ran great. I think i need to
go for the coils though. I will do this in spring and swap plugs again, turbos eat plugs for breakfast.