Jump to content
  •  
Advertise here

Grand Cherokee 4.0 Sluggish Performance


Recommended Posts

I'm with Fred, shoot your mechanic.

Seems like a case of blocked exhaust to me too. Simple check by hand while reving to see if the exhaust is blowing out enough.

At night drive your car around for a good while then park in a dark spot and give it revs and then get under and see if part of the exhaust is glowing red.

  • Like (+1) 5
Link to comment
Share on other sites

36 minutes ago, desertdude said:

I'm with Fred, shoot your mechanic.

Seems like a case of blocked exhaust to me too. Simple check by hand while reving to see if the exhaust is blowing out enough.

At night drive your car around for a good while then park in a dark spot and give it revs and then get under and see if part of the exhaust is glowing red.

Good idea I will try this as well. 

  • Like (+1) 2
Link to comment
Share on other sites

2 hours ago, desertdude said:

I'm with Fred, shoot your mechanic.

Seems like a case of blocked exhaust to me too. Simple check by hand while reving to see if the exhaust is blowing out enough.

At night drive your car around for a good while then park in a dark spot and give it revs and then get under and see if part of the exhaust is glowing red.

That’s what I was getting to with computer diagnostic too. Less air coming in means less air going out which means blocked cat. I would unbolt the cat from the manifold and go for a sprint to see if you gain the power back, obviously if it’s safe and you’re not going to have flames coming out on petrol lines etc. The proper way to do it would be to remover the front lambda sensor out and screw in a back pressure tester but not everyone is going to have one of those. 

  • Like (+1) 3
Link to comment
Share on other sites

11 minutes ago, Barry said:

That’s what I was getting to with computer diagnostic too. Less air coming in means less air going out which means blocked cat. I would unbolt the cat from the manifold and go for a sprint to see if you gain the power back, obviously if it’s safe and you’re not going to have flames coming out on petrol lines etc. The proper way to do it would be to remover the front lambda sensor out and screw in a back pressure tester but not everyone is going to have one of those. 

Better I will visit you this Saturday. It will be way easier. 

  • Like (+1) 3
Link to comment
Share on other sites

34 minutes ago, Barry said:

That’s what I was getting to with computer diagnostic too. Less air coming in means less air going out which means blocked cat. I would unbolt the cat from the manifold and go for a sprint to see if you gain the power back, obviously if it’s safe and you’re not going to have flames coming out on petrol lines etc. The proper way to do it would be to remover the front lambda sensor out and screw in a back pressure tester but not everyone is going to have one of those. 

This just the more direct, fast and no tools or faffing about required approach.

Two different methods to look for the same result.

Because I remember long before diagnostics tools were cheap and only available to dealers. Had a Land Cruiser with the same issue. Everything checked out but car was sluggish.

After a long day of looking for the issue decided to call it a day and when switched off the lights of the garage saw a glow coming from under the car. Looked under the car and the exhaust was glowing orange and viola culprit was found.

2 hours ago, sertac said:

It has some weird non off road bumpers 

It's just a bolt on ricer ground effect kit, can't you see with the bling wheels it was a mall crawler all it's life. Which is actually good news knowing it was never  abused off road.

Probably has a big bass bin the back too! Lol!

  • Like (+1) 2
  • Haha (+1) 2
Link to comment
Share on other sites

Tonight I drive around half hour when I got close to home I kept the gear ar 1st and drive with high rev. Than I park to a dark spot and keep revving bit more. After that I check the underneath but nothing glowing. I check the exhaust outlet air is coming out. 

  • Like (+1) 1
Link to comment
Share on other sites

1 hour ago, sertac said:

Tonight I drive around half hour when I got close to home I kept the gear ar 1st and drive with high rev. Than I park to a dark spot and keep revving bit more. After that I check the underneath but nothing glowing. I check the exhaust outlet air is coming out. 

Air will be coming otherwise you car won't run at all. But what is the amount and pressure. You checked the simple way. Now check the technical way Barry mentioned

  • Like (+1) 1
Link to comment
Share on other sites

34 minutes ago, desertdude said:

Air will be coming otherwise you car won't run at all. But what is the amount and pressure. You checked the simple way. Now check the technical way Barry mentioned

Yes that's the way so this Saturday I am planing to visit him

  • Like (+1) 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

Terms of use