Restoring lost horsepower with a damn good service

[piggoy]

When I come to service my 172 in a couple of months I'm thinking of doing things a little differently. Until now my 172's engine has always been serviced with bog standard replacements, e.g oil, oil filter, airfilter, sparkplugs. The belts have been done at the prescribed intervals. I've never dyno tested my car but I do wonder how down it may be on the spec 169bhp after 9 years. What steps can I take to restore horses that have been lost over these years? Short of a complete engine rebuild I've compiled a list:

- Clean airbox
- ITG panel filter
- Clean throttle body
- Clean interior of intake plenum
- Clean lower intake manifold
- Ultrasonic injector cleaning or replacement
- Fuel treatment/ Redex stuff?

Your comments would be much appreciated. Please feel free to tell me I will be wasting my money with any of these ideas

 

[Tom@JMS]

Spark plugs.

 

[Dave.]

make sure you use the NKG pfr6e-10!

 

[Bassplayer]

Change fuel filter too. Use an oe filter. Pollen filter? The injectors are a moot point. Some years ago I was always getting them done for customers. Now, with petrol being better, at least Shell / BP/ Texaco etc there is not so much call. However, if you get any stuttering or poor idle it may be worth getting them done. Don't buy new as they are often not too clever! Otherwise sounds good. Clean the breathers too. And flush the engine. Keep off the supermarket petrol and it will be great. Change the gearbox oil and the brake fluid if you really want to go to town.

 

[Jay.S]

a pipercross panel filter is also less restrictive and cheaper.

 

[Danith]

i had the wrong plugs fitted in mine by the guy who owned the car before me, fred whacked in 4 of the proper ones in when doing my belts and i noticed a marked improvement in both MPG and engine response on the drive back up to manc.

but then again you've probably got the right ones in already so irrelevant to you!

 

[Dave.]

people often use bosch super 4's, terrible!! i had to stick a set in my car once as i had a plug go and i was in france! ran terrible!

 

[Danith]

don't think the ones in mine were even those! the receipt says £9.60 for all 4!

 

[Fred@BTM]

i had the wrong plugs fitted in mine by the guy who owned the car before me, fred whacked in 4 of the proper ones in when doing my belts and i noticed a marked improvement in both MPG and engine response on the drive back up to manc.

but then again you've probably got the right ones in already so irrelevant to you!

that was mainly down to you cam timing being a mile out

 

[Danith]

that was mainly down to you cam timing being a mile out

ah right. thats also a good point yes! it definitely feels better though. I took it for a quick blast tonight seeing as i won't be using it for a while! think that btm sticker has given it an extra 5 bhp too!

 

[piggoy]

What would people recommend for cleaning the inside of the plenum and manifold? Any special solvents or just good old fashioned elbow grease?

 

[Tom@JMS]

Blow out with brake / clutch cleaner - then a dam good blow with an air line.

 

[TheEvilGiraffe]

Can't see the point TBH. Might want to wipe up the gunk that collects at the bottom of the butterfly but other than that, there'll be nothing worth cleaning in the inlet manifold. Any idea how fast air is moving through there ? :rasp: