2001 Mitsubishi Montero Sport XLS suddenly acting sluggish!

[swc220]

Hi, I have an automatic 2001 Mitsubishi Montero Sport XLS.Lately it has been acting sluggish. Its a little hard to explain but while I'm driving, usually at a low gear, it will tend to just kind of lose power. You can feel it. The car will feel as if its lost all power for a split second and then continue on as before. It also has been pretty slow to accelerate at low speeds (especially after I haven't used it for a few hours). Besides all that the most noticeable difference was how bad my vehicle switches gears especially if I don't crawl to a higher speed at second and third gear. It kind of chokes otherwise and is also the most noticeable if the montero hasn't been used in a few hours. This is my first vehicle purchased from my friend. It has about 166,000 miles on it and he never did a transmission flush for the five years he had it. a used air intake valve was also installed about 5 months ago because of the montero turning on but sputtering and then turning off, so it had to do with the gas not flowing correctly. that's about all I can think of. Any thoughts?

[sport03]

When's the last time it got a tune up (plugs and wires)? Is the service engine soon light on at all?

[swc220]

I don't think so but it probably hasn't had one in a while.

[Naeos_Valkarian]

Feb 10, 2016 4:43:33 GMT -5 swc220 said:

Hi, I have an automatic 2001 Mitsubishi Montero Sport XLS.Lately it has been acting sluggish. Its a little hard to explain but while I'm driving, usually at a low gear, it will tend to just kind of lose power. You can feel it. The car will feel as if its lost all power for a split second and then continue on as before. It also has been pretty slow to accelerate at low speeds (especially after I haven't used it for a few hours). Besides all that the most noticeable difference was how bad my vehicle switches gears especially if I don't crawl to a higher speed at second and third gear. It kind of chokes otherwise and is also the most noticeable if the montero hasn't been used in a few hours. This is my first vehicle purchased from my friend. It has about 166,000 miles on it and he never did a transmission flush for the five years he had it. a used air intake valve was also installed about 5 months ago because of the montero turning on but sputtering and then turning off, so it had to do with the gas not flowing correctly. that's about all I can think of. Any thoughts?

Personally I would start with a transmission flush, if that doesn't work I'd go and have the spark plugs and wires changed out. It also wouldn't hurt to run some injector cleaner through the engine and check your air filter. If the filter is dirty enough you can experience a lack of horses which can translate into that sluggish feeling although admittedly this is unlikely. 

[jkdv8]

Fuel filter change wouldn't hurt either.

[Naeos_Valkarian]

I know it's a little off topic but when was the last time the timing belt/water pump was changed? If you don't know when it was done and your friend is unsure then it's time to get them replaced. I only bring this up because if the belt fails then you can wind up with a totaled engine and at 166K miles it sounds like it's about time to be done.

[greaser220]

Its most likely over due for the full package. Ill start with a transmission flush and go from there.

[colted]

I concur with greaser.....have a tranny flush from Mitsubishi using Diamond SP-III.

[redraif]

Feb 10, 2016 22:14:42 GMT -5 colted said:

I concur with greaser.....have a tranny flush from Mitsubishi using Diamond SP-III.

Absolutely Mistu fluid ONLY! Just having the wrong fluid in there (non-Mitsu) can cause a host of issues with drivability.

Since you bought it from your friend ask what maintenance has been done. This is very important to help diagnose the possible issues.