My 2000 DII with 132,00kms (82,000miles) has progressivly been getting worse hesitation problems under gentle acceleration. It is getting to the stage that passing other vehicles is dangerous.

Recently, if coasting from a higher speed down to 60kmh (40mph) and then gently accelerating again it is really labouring to pick-up speed and seems reluctant to downshift. If I kick-down it will dowshift to the lower gear but under gentle acceleration it will not.

I have also noticed when driving at 60kmh (40mph) in 3rd it hesitates less but when I shift to D it gives a very brief boost of power before changing into 4th / OD.

I do not have any dash lights on (except the three amigos - don't get me started). I have noticed having to top up the coolant recently, nothing drastic but a little more than usual.

I have had new plugs / wires, transmission flush, oil & filter change, MAF cleaned, seafoam in the intake & tank all done within the last couple of months.

Any thoughts or suggestions ?

thanks guys
skrams

 

If it's idling OK, sounds to me like it might be exhaust backpressure. How are your cats?

 

Idle seems to be ok, no stalling or fluctuations in rpm. I am not sure how the cats are. What should I look for.

 

Look for mice.

If you have lots of mice you know your cats aren't working.

Seriously - When mine went bad on another car I could floor the accelerator and it wouldn't go over 4,000 rpms - that's how I knew it was bad.

 

I'm told that if the cats rattle, they've had it.

Another way to test is to get a scan tool that will plot your pre and post cat oxygen sensor output. If the post cat sensors track the pre cat sensors very closely (instead of sort of drifting up and down more slowly), your cats are toast.

Maybe the best way to deal with the problem you are having is to actually test exhaust back pressure. Here's a cheap test kit (cheapest I could find on the net). http://www.tooldiscounter.com/ItemDi...kup=STATU-29PB

I could be wrong. But similar to Aquaholic, I had a car that had clogged cats and it pretty much couldn't get out of its own way to try to accelerate, even though it would idle smooth as a kitten.

This was back in the "good old days"quite a few years ago.To fix it, I pulled the cat, cut it open, removed the clogged honeycomb, welded the case back together, and drove off into the sunset with no failed state emissions test issues. Now in modern day, you would have to diagnose the problem more specifically and pop for new cats if they've croaked.

 

Took it for a drive today. Drove it in 2nd gear at 3,500rpm + for a short distance a few times when the road was clear. It seems to be driving better, not cured, but better. Could that have cleared something ?

 

If you floor it in D and keep it floored up to highway speeds - does it feel as if it looses power when the RPMs get high shortly before shifting to the next gear? If it does you likely havea stoppage. I didn't see air filter in your list of things you changed - it sholud be changed if it hasn't.

 

I will try that on my way home. Yes, air filter has been changed in the last couple of months. When you refer to a stoppage, what exactly do you mean ? A blockage in a line !

thanks

 

It does not appear to loose power shortly before shifting. When I accelerate hard the hesitation is hardly noticable. Only when in traffic and gentle throttle does it seem reluctant to shift out of OD.

 

Bought an OBDII code reader today. No codes other than P1590 - Rough Road. I was hoping for a couple of codes to shed some light on the subject, but no luck.

What now.