High Mileage Isuzu Rodeo enters a lumbering giant mode

I just picked up a 1995 Isuzu Trooper -v6,



It is a 5 speed manual and a few times, even in first gear I seem to have high RPMs but it seems like it does not have any power and has the same problem in all the other gears as well… I was able to get it upto 65 on the freeway but it took awhile to reach it because if i applied more gas it only seemed to just rev up the rpms but not make the vehicle move faster. I was able to slowly increase speed by keeping the rpms at a decent lower range but had no pick up as it has normally. It just feels like it’s a lumbering giant.



Today it was working fine until I got gas, and then started to act like a lumbering giant. When I started it back up after work, it was back to normal.



It seems to enter Lumbering Giant Mode when it’s warmer out than colder… or if I have had a longer drive. Waht could be causing this?



Or am I just changing gears improperly?



BTW it’s not a 4x4.

First of all, please clarify whether this is a Rodeo or a Trooper, as they had different engines, as well as other mechanical differences.

That being said, one problem (high revs, little acceleration) sounds like a badly slipping clutch. The other problem (hesitation after gassing up) sounds like a problem with the evaporative emissions system. If you have both problems, you should be prepared for a bill repair bill, unfortunately.

Did you have this vehicle inspected by your mechanic prior to purchase?

oops… yes it is a Rodeo… not a Trooper… but as far as the gas trip… it started acting as the Lumbering Giant after I got gas… which is the same problem… I’m starting to guess it is the clutch then…

I’m really not sure that I understand the “Lumbering Giant” reference.

Is this reference a duplication of the high revs/poor acceleration syndrome, or is it something different? A slipping clutch is not likely to act differently with temperature variations, and you did state that the “Lumbering Giant” situation was worse in warmer temperatures, thus leading me to believe that there are two separate problems–especially in view of the reference to the “Lumbering Giant” revealing himself after you filled the gas tank.

Nobody can give you an accurate diagnosis from afar. Please take this vehicle to a competent mechanic (NOT a chain) now, even if you did not take it to a competent mechanic before deciding to buy it.

Actually, when the clutch gets hot, it may slip more. Increased heat reduces friction. I’d say clutch, though it could be an adjustment only, but with a 95, it’s probably at a point where it should be replaced. I’m impressed, I got to 85K in my Ranger (95 model, new clutch in 2004) though that was due to a failed slave that required pulling the tranny anyway.

On a manual transmission, the engine should be directly connected to the back wheels so if the RPM’s go up but the vehicle doesn’t speed up as much as it should it’s a clutch problem. Luckily the clutches on the non-4wd versions are pretty easy to change and it shouldn’t be too expensive as far as clutch replacements go.

The problems after fill-ups might be some sort of EVAP or tune-up issue, but I don’t really think a meaningful diagnosis can be made until the clutch issue is fixed.