Any suggestions for the owner of a 3.5yr old Octavia Diesel (100BHP) which just hasn't felt "quite as fast" for the past few months, and whose fuel economy has also dropped?

A bit vague I know but if there's any specific info you need to help your diagnosis just shout

Whats the air filter like?

Whats the air filter like?

Thanks Andy. That was my first thought (no, I tell a lie: my first thought was "spark plugs" (he mentioned flat spots) but then I switched me brain on ). I just wasn't sure how a clogged air filter would decrease economy?

But anyway as I know that it's only a simple job to check I'll have a look.

Air filter would be first port of call and probably run a few tanks through of premium diesel like Shell Extra which is meant to help clean out the system....

Chris

Millers Diesel Clean Plus is the stuff to use. Keeps the fuel system clean and improves performance, both shove and economy.

Can you get hold of diag tool like VAG COM? Theres a real easy check to do on your air mass meter, sounds like it may well be failing.

Can you get hold of diag tool like VAG COM? Theres a real easy check to do on your air mass meter, sounds like it may well be failing.

MAF? :eek: VAG COM: Possibly - which blocks should I look for?

Edit: PS it's not my car

*todddles off to search for Mercedes MAF for a diesel...*

I'll look up the blocks tomorrow, cant remember them off the top of my head at the moment...dog (must be the heat).

MAF's are now availalbe from VAG as exxhange units btw and have come down drastically in price,some about

Thanks for that.

I've just noticed a rash of "my diesel doesn't work in heat". Does anyone happen to know whether the 100 diesel octy has an intercooler? Otherwise it might suffer more than most with heat.

Although thinking about it I expect it probably does

Yes it does, mounted on the o/s/f

Hello Ross, any luck with values / parameter ranges?

Try value block 113

Should give a comparison of air mass in mg. One will show expectedand the other will show actual. Ideally you want them to stay pretty close to each other (within say 100-150). If you air mass is kanckered under full throttle (I find low speed third gear then foot down works best) it will prolly read around 400-500 mg. Spec iirc should be around 800 or so but it will tell you what it should be.

hth's

Try value block 113

Should give a comparison of air mass in mg. One will show expectedand the other will show actual. Ideally you want them to stay pretty close to each other (within say 100-150). If you air mass is kanckered under full throttle (I find low speed third gear then foot down works best) it will prolly read around 400-500 mg. Spec iirc should be around 800 or so but it will tell you what it should be.

hth's

I'm sure it will help enormously. I'll keep the board updated.

Just one small question, the units; I'd have expected mass/time ie g/s. What are "mg"s?

Remember it is German diagnostics

I could theorise but I dont know for sure, I just know what the reading should be