Mazda3 Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
I have a 2008 Mazda 3 hatch with a 2.3 I4. Whenever I’m on the highway and I cruise towards 60 the car makes a huge clunk and the car continues to drive perfectly fine after. But this is no ordinary clunk, it’s a hard jolt forward. Best thing I can think of right now is the throttle body.
 

·
Registered
Joined
·
247 Posts
does it do it in a lower gear, ie higher rpm at same speed, or rpm related
does it do it when you decelerate through 60
manual or auto
 

·
Registered
Joined
·
5 Posts
Discussion Starter #3
we
does it do it in a lower gear, ie higher rpm at same speed, or rpm related
does it do it when you decelerate through 60
manual or auto
It’s in 5th gear. The car steadily holds 2k rpms. It happens when I decelerate as well. The car is an automatic
 

·
Registered
Joined
·
5 Posts
Discussion Starter #4
we

It’s in 5th gear. The car steadily holds 2k rpms. It happens when I decelerate as well. The car is an automatic
The car never does the hard jolt when going under 60. Only happens on the highway. I can’t find anything similar about this situation.
 

·
Registered
Joined
·
160 Posts
I presume the Check Engine light (CEL) isn't illuminated... However, can you scan for OBD-II codes immediately after a drive when this happens, so you can assess for pending codes [from the transmission]? A pending code wont set the CEL. I think this seems more like a transmission or TCM issue, rather than the throttle body.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
I presume the Check Engine light (CEL) isn't illuminated... However, can you scan for OBD-II codes immediately after a drive when this happens, so you can assess for pending codes [from the transmission]? A pending code wont set the CEL. I think this seems more like a transmission or TCM issue, rather than the throttle body.
Well there was a CEL but it went away on its own. I have to wait until Monday to get my hands on a code scanner. I’ll come back here and posts the codes to get an opinion from you all. I appreciate the responses!
 

·
Registered
Joined
·
160 Posts
Well there was a CEL but it went away on its own. I have to wait until Monday to get my hands on a code scanner. I’ll come back here and posts the codes to get an opinion from you all. I appreciate the responses!
FWIW, I believe every major parts store in the US offers free OBD-II scanning, a courtesy and way of drumming up business. If a CEL gets set, or the "jerk" happens before Monday, consider stopping by an auto parts store to have them scan for pending or set codes.
 

·
Registered
Joined
·
1 Posts
I have a 2008 Mazda 3 hatch with a 2.3 I4. Whenever I’m on the highway and I cruise towards 60 the car makes a huge clunk and the car continues to drive perfectly fine after. But this is no ordinary clunk, it’s a hard jolt forward. Best thing I can think of right now is the throttle body.
SAME ! And my clutch Master cylinder just went out I think , im just touching 130k
 

·
Registered
Joined
·
160 Posts
SAME ! And my clutch Master cylinder just went out I think , im just touching 130k
Well, a manual transmission may have a different issue all together. However, in the off-chance that these are related, have you [both] ensured that your motor mounts are good? If you're getting a unsettling jolt without clear, forced RPM or speed changes, perhaps something is up with the mounts that manifests with the mix of vibrations and torques at particular speeds.
 

·
Registered
Joined
·
6 Posts
I have a 2008 Mazda 3 hatch with a 2.3 I4. Whenever I’m on the highway and I cruise towards 60 the car makes a huge clunk and the car continues to drive perfectly fine after. But this is no ordinary clunk, it’s a hard jolt forward. Best thing I can think of right now is the throttle body.
Hello, Check this video out, and see if you have the same problem
 

·
Registered
2012 Mazda 3 GX MT5
Joined
·
110 Posts
Sounds like the TCM ... but to be sure ..tie down the dead body in the trunk when you are doing that get away
 

·
Registered
Joined
·
7 Posts
I'm sure you are already in 5th gear by the time you are at 60MPH, but just wanted you to be aware that IF the hard jolt is occurring when it shifts between 3rd to 4th gear (known as "shift shock"), then that is likely due to a faulty transmission which wasn't fixed until the 2009 model years. See this TSB: http://noes.net/05.10.10.pdf

Note that there is also an aftermarket toolkit to fix a transmission with this issue, shown here: 4F27 | Northland Automatic Transmission Service Inc.

The issue is caused by a servo pin's bore hole getting worn.
 
1 - 14 of 14 Posts
Top