Shudder in park, check gauges light

[BlazinIdeas]

First off, I'd like to point out that I am very new to this forum and also to forums in general, so please forgive me for any newbie mistakes I will inevitably make. Secondly, I have searched and searched and I cannot seem to find an issue similar to mine. I was hoping you guys could really shed some light on it.

Ever since I bought my TB, it has a slight shudder in park. The RPMs will go up slightly then drastically drop and then resume regular idle. It is very sporadic, but has recently gotten worse and more often. A few days ago, I was just about to leave a friends house, and I started her up and send a few last minute texts before I left. Well, I noticed the TB was shuddering quite a bit, and then suddenly the RPMs dropped so low, she cut off and my check gauges light came on. Any ideas? I was thinking that maybe if I did the recommended throttle body clean, this might help.

A couple other issues that might be related also would be a subtle shudder while going about 40-50 mph, and an occasional hard shift.

If there is a thread somewhere already on this topic, please kindly direct me to it and I'll apologize for making an unnecessary thread.


Thanks ahead!

 

[Mounce]

Check engine light on?

Check gauges light probably came on due to oil pressure plummeting when it died.

Ever cleaned your throttle body?

 

[BlazinIdeas]

Yes, the SES light has been on.

No I haven't. I've only had the truck about a month, and I've been on vacation for about half the time. When I am off, I will clean the throttle body. Any other ideas?

Also, the previous owner told me the SES light is usually on because it is missing an 02 sensor so I haven't worried too much about it.

 

[Mounce]

Need to get the codes read, might be something other than what he said and if it is missing an o2 sensor it should be replaced so that it's code won't hide other codes that come up. Parts stores will read them for free, just write them down and relay them to us.

The place we got ours from also said the code was for an o2 sensor, turned out to be thermostat and it's never thrown a code for either o2 sensors.

 

[BlazinIdeas]

Alright I'll run by today. Thanks.

 

[Mooseman]

It's not a good idea to run the truck without a functioning O2 sensor. That's the primary means it determines how much fuel to deliver to the intake. Now it's just "guessing" which will likely cause excessive fuel use and poor engine performance.

Check the codes, replace the O2 sensor, clear the codes and run it a while.

 

[gmcman]

It's not a good idea to run the truck without a functioning O2 sensor. That's the primary means it determines how much fuel to deliver to the intake. Now it's just "guessing" which will likely cause excessive fuel use and poor engine performance.

As well as likely destroying your catalytic converter.

 

[C-ya]

A couple other issues that might be related also would be a subtle shudder while going about 40-50 mph, and an occasional hard shift.

Welcome! I have some family in the Hazel Green area.

This shudder may be the PWM/TCC lockup issue that a lot of folks have fixed with a repair kit from ebay/amazon like this one: Link.

 

[BlazinIdeas]

It's been a good minute since I've posted in this thread, but with starting college and working, I've been really busy.

Anyways, shortly after posting this thread, I cleaned my throttle body, did an oil change, and replaced my O2 sensor. She ran pretty dang good, but my mpg is still pretty bad. About 12-13 miles a gallon and I'm just at a loss. Also, last week I noticed that my truck isn't shifting in fourth gear (OD) and it's starting in second gear. I can't manually shift into first either. I've searched and searched but I am at a loss. Cruising at 55-60 mph and my RPMs are at about 2500-3000 compared to the usual 1500-2000 so that's skyrocketing my gas consumption. I have about a 30-35 minute commute to school everyday so I'd really like to get this fixed soon.

Any ideas? I'm really not trying to rebuild or replace this transmission.

 

[Mooseman]

Did you check your shifter linkage? Normally, when you have in 2nd gear, it will start in that gear (used for winter takeoff in snow). If the linkage is fine, it could be an internal issue with the tranny.

 

[BlazinIdeas]

How exactly do I check that?

 

[Mooseman]

Check the linkage physically for damage or breakage. You might need and assistant to go through each gear and see if it moves freely at the transmission. If that checks out, an internal issue will likely require a transmission shop.

 

[BlazinIdeas]

Okay thanks. After school today I'll check it out