hello to everyone. I am brand spanking new to this forum and I find the TECH very informative as well as many other people registered here. I have a 2002 s40 and it seems to have a hard time accelerating. It revs pretty loud and it it yanks when it shifts sometimes. Another thing the car does is sometimes when I put it in drive and I give it gas it takes a second to register that im pressing on gas. When I put the car in reverse, sometimes the gas pedal doesnt even register, it seems like its just rolling back? The car now has 85000 miles on it( I know im a highway driver, lots of miles) any clue anybody? My check engine light is reading 3 codes. one is p0301 and p0304. the 3rd is p0128. Cylinders misfire and colland below level. Should i replace spark plugs and thermostat?

 

if cylinders are missfiring.......
id go with the spark plugs, then if that doesnt work you'll have to change the coils....haaha i think....

 

whats the haha for? it seems as if everyone has problems with spark plugs and coils? any recomendation on brand to purcase? Thanks for your help.

 

I think the service interval for plugs on a 2002 S40 is change every 45000 miles. I would go with Volvo plugs as Volvo's are notorious for "eating" plugs other than OEM. I have never had coil problems with my 2002 S40 but there are posts here from people who have had. I beleive that the S40 has two coils, they can be checked by a dealer to see if they are properly functioning. If bad replace both.Check your coolant level and be sure it is topped up, also the fluid reservoir before you start replacing parts.You may find that the temp sensor needs to be replaced.

 

ya id go with the volvo plugs, a lot of other brands of plugs cause problems especially bosch plugs! and do what hocbj23 said...ahah, ya alot of plugs and coils need to be changed its almost like the flu going around!

 

Tell me about it, i had mine done at christmas and thinking i need to do them again.

 

I agree with everyone. Start with the plugs and see what happens. That might fix all your problems.