So, I signed up for an account to post this question. I have taken my truck to four different Toyota dealerships with this problem, and none of them have been able to correctly diagnose it or fix it. I'll go into more detail about what all has been done after I describe the problem.
Model: 2008 Tacoma SR5 extended cab, 4 cylinder engine, 5-speed manual transmission, 4x4 with 236,000 miles.
About a year ago, I noticed my throttle was sticking while shifting between 4th and 5th gears. I can reproduce the problem at will. Basically, engine gets up to 2,500 to 3,000 RPM in 4th gear or 5th gear. I engage the clutch, and the RPMs don't change for several seconds, then slowly start to rev down to normal idle. Depending on the starting RPMs, it takes 12 to 15 seconds to do this. This happens whether I leave the truck in gear or put the transmission in neutral, as well as if I put it in neutral and let out on the clutch pedal. However, I can force the throttle to "unstick" at any time by punching the accelerator briefly and the RPMs immediately return to normal.
However, I cannot reproduce this problem in 1st, 2nd, or 3rd gear. The RPMs immediately return back to idle if I engage the clutch in those gears. The behavior only occurs in 4th and 5th. That kind of rules out a throttle problem in my mind, but I'm not an expert on this.
At the same time, I was hearing a gurgling sound coming from behind my dashboard. I thought they were unrelated, but was told differently by one dealer.
Here's what's been done so far
1: Replaced thermostat to fix gurgling sound. No effect.
2: Throttle assembly removed and inspected. Found no problems, cleaned it and put it back in. No effect.
3: Replaced some hoses on the cooling system. No effect.
4: Replaced clutch. (I was suspicious of this because the clutch had just been replaced 40,000 miles ago.) No effect, so I wrote a nasty e-mail to the GM, and they agreed to waive my diagnostic fees and take another look at no charge.
5: Replaced head gasket. I was told this was the cause of both problems because of how coolant is routed through the clutch. They replaced the head gasket, timing chain, timing chain cover, and water pump, all at no charge, which was more than fair in my mind. However...
This last repair fixed the gurgling sound, and I thought it had fixed the throttle problem as well because I couldn't reproduce it on the way home from the dealer. However, less than 200 miles later and we're back to the original throttle symptoms I described above.
I'd pull my hair out if I had any. What the hell is going on with my truck where this problem can occur only in 4th and 5th gears, but not in the lower 3 gears??? My instinct still says throttle problem, but if that was the case, wouldn't it stick at 3,000 RPM regardless of what gear I was in???
I'm done going to dealerships until I can arm myself with more information. Has anyone experienced ANYTHING like this before? Does anyone have any ideas?
Thanks in advance,
Riff
Model: 2008 Tacoma SR5 extended cab, 4 cylinder engine, 5-speed manual transmission, 4x4 with 236,000 miles.
About a year ago, I noticed my throttle was sticking while shifting between 4th and 5th gears. I can reproduce the problem at will. Basically, engine gets up to 2,500 to 3,000 RPM in 4th gear or 5th gear. I engage the clutch, and the RPMs don't change for several seconds, then slowly start to rev down to normal idle. Depending on the starting RPMs, it takes 12 to 15 seconds to do this. This happens whether I leave the truck in gear or put the transmission in neutral, as well as if I put it in neutral and let out on the clutch pedal. However, I can force the throttle to "unstick" at any time by punching the accelerator briefly and the RPMs immediately return to normal.
However, I cannot reproduce this problem in 1st, 2nd, or 3rd gear. The RPMs immediately return back to idle if I engage the clutch in those gears. The behavior only occurs in 4th and 5th. That kind of rules out a throttle problem in my mind, but I'm not an expert on this.
At the same time, I was hearing a gurgling sound coming from behind my dashboard. I thought they were unrelated, but was told differently by one dealer.
Here's what's been done so far
1: Replaced thermostat to fix gurgling sound. No effect.
2: Throttle assembly removed and inspected. Found no problems, cleaned it and put it back in. No effect.
3: Replaced some hoses on the cooling system. No effect.
4: Replaced clutch. (I was suspicious of this because the clutch had just been replaced 40,000 miles ago.) No effect, so I wrote a nasty e-mail to the GM, and they agreed to waive my diagnostic fees and take another look at no charge.
5: Replaced head gasket. I was told this was the cause of both problems because of how coolant is routed through the clutch. They replaced the head gasket, timing chain, timing chain cover, and water pump, all at no charge, which was more than fair in my mind. However...
This last repair fixed the gurgling sound, and I thought it had fixed the throttle problem as well because I couldn't reproduce it on the way home from the dealer. However, less than 200 miles later and we're back to the original throttle symptoms I described above.
I'd pull my hair out if I had any. What the hell is going on with my truck where this problem can occur only in 4th and 5th gears, but not in the lower 3 gears??? My instinct still says throttle problem, but if that was the case, wouldn't it stick at 3,000 RPM regardless of what gear I was in???
I'm done going to dealerships until I can arm myself with more information. Has anyone experienced ANYTHING like this before? Does anyone have any ideas?
Thanks in advance,
Riff
