2002 270,000kms es300
Jolting/stuttering
This issue is kind of intermittent but has happened before for a few months then went away / was fixed for a few months and has now returned. Seems to be: From stationary, and 1st gear under 40km/h, when medium throttle & high engine load is applied, the car will have affected acceleration from 900-2k rpm and it stutters/struggles, slowly climbing, then for a second stays at an rpm and rattles/pops, most noticeably at 2k and then it clears up and I have my normal power band. Light throttle & lower engine load is usually smooth. Also in 5th gear when cruising at around 1.9k rpm it jolts once or twice then stops for a few seconds then jolts. Only happens when this other issue was happening so for sure related but it makes me wonder transmission or engine? Or something random smh. Oil and trans fluid levels look good. Last time it seemed to go away when I repaired a cracked intake hose but everything still looks good.
Thank you for reading, any ideas highly appreciated

 

Hello,

Hard to tell anything without being able to actually feel the issue in question.

Start with a general check under the hood, see if anything is loose, or if you can hear any air hissing past the Intake. If you have an OBD2 Scan Tool, take a snapshot of All the Parameters you can access withing the Engine Live Data, do so with the Engine Fully Warmed and at Idle, and with the Transmission in Park, then post it here.

You can also try Disconnecting the MAF Sensor to see if that will have any effect on the behavior. When the Sensor is Disconencted, the Engine should remain running more or less normally, outside of more Sluggish Response and considerably worse Fuel Economy, you shouldn't really feel that much of a difference, but if you do, it could indicate an issue with the Air/Fuel Mixture, mostly likely caused by a Vacuum Leak.

Hope this helps and best of luck!

 

Connected a new OBD scanner and it doesn't recognise the car. I recall this happening ever since I owned it but I just thought my scanner was broken. What could possibly cause that?? Scanner turns on so isn't the fuse but I double checked it anyway. Also this caused VSC and TRC lights to come on (not an issue as wanted this disabled anyway) but I've read that it could be a sort of backup engine light which is what I suspect. Also ABS now flashes when I'm stationary (do you know how to just disable these systems?) Tried the MAF unplug and immediately stalled. Audible hissing from the two upper plenum gaskets so will get onto those asap. Any ideas on the incompatibility with OBD scanners ?

 

Replying to myself as I saw another thread explaining the TRC VSC lights issue, my next question would be does this mean the systems are disabled or just the lights on? Still need to figure out why scanner not connecting at all though..

 

Why would you even want that anyway..?

What Scan Tool are you using? From its behavior, as strange as it may sound, it could be that your Scan Tool is incompatible with your car. Despite identical connectors, OBD2 Standards uses a variety of different Communication Protocols, depending on the Manufacturer of the vehicle and the Year of production, and although even Generic Scan Tools should be able to support all the common ones, selecting the correct one automatically, some Scan Tools are less capable than others, which could be the cause for your issues.

To test it, try stopping by any Major Parts Store, as most of them do have capable Scan Tools that they can loan to you for free, see if the tool they have will have a better luck communicating with your car. You can also try connecting your existing Scan Tool to any other car that you can access to see if it would have the same issues.

Well, that would explain it..

Hope this helps and best of luck!