Heat induced LIMP mode. No error codes! - Honda-Tech

Heat induced LIMP mode. No error codes!

Thread Tools Search this Thread
Old 03-29-2016, 01:02 AM   #1
Trial User
Thread Starter
Join Date: Mar 2016
Posts: 1
Default Heat induced LIMP mode. No error codes!

Hi All:

I've got a 2008 Accord, Japanese model, with a 2.4l i-VTEC (K24Z2), 58,000 miles. Totally stock. I guess this is more like an Acura TSX than an Accord, see here.

After about an hour of highway driving, often heavily loaded with my entire family of 4 and luggage, the engine begins to rev limit. I begin to notice it at about 4500 RPM, but it steadily declines, over a period of about 20 minutes, until it as low as 2000 RPM.

I'm in a warm place, and temperatures are often 85 F or higher. Cool mornings do seem to delay the problem, but only delay by about an hour, not remove.

By rev limit, I mean that the fuel is cut to the engine at that RPM. The tach needle bounces around the limit value until you let your foot of the gas and go to a lower RPM. Look into LIMP mode if you're unfamiliar with this behavior.

Restarting the engine restarts the process. I get about 15-20 minutes, depending on temperatures and how long I've been driving, to drive with higher rev limits, but eventually it gets down to around 2000 and I have to restart again. Several times, I've had to limp home by putting the car into neutral and restarting the engine while it coasts, every 15 minutes, for 1-2 hours. I do this especially on approaches to hills or when needing to overtake a vehicle.

Around town, it's cool. No problem for 15-30 minute drives.

Now, the hard part. There are no error codes! The check engine light does not engage. I have confirmed that the CEL does light by starting it with the VTEC solenoid unplugged. The oil level is perfectly between high and low. The temperature gauge looks great, well under the half way point. Fluids are good. I recently changed the oil to OEM synthetic 5W-20 and filter. I recently replaced the VTEC solenoid. I've checked ground wires and looked at all major sensor connections, especially the oil pressure sensors. Nothing amiss. The engine compartment is super clean. I've disconnected the negative battery terminal to reset the ECU. In spite of these efforts, the problem remains.

I've located one post of a similar problem on a Honda:

CRV loses power and stutters at high RPM in hot weather.

And seen many other LIMP related problems, but usually only on cars that throw a lot of error codes and are older/heavily modded.

Questions to the community: Any ideas? Alternator, choked catalytic converter, damaged ECU, and timing chain tooth missing are what I think are current possibilities. If you could add to or remove an item on this list based on my description I'd be eternally grateful. Also interested in diagnostic advice. I've got a very limited set of tools here.

Jesse Johnson is offline   Reply With Quote
Old 03-31-2016, 10:59 AM   #2
Honda-Tech Member
iTrader: (3)
pogeeboy27's Avatar
Join Date: Aug 2005
Location: Honolulu, HI
Posts: 584
Default Re: Heat induced LIMP mode. No error codes!

Try bleeding your cooling system. There might be a pocket of air trapped somewhere in the cooling passages of the engine which causes the area around the temperature sensor to get hot. I've experienced this same exact scenario in my K20 swapped Civic. I used the kit listed below to bleed my cooling system and can confirm it works.

Amazon.com: Lisle 24610 Spill-Free Funnel: Automotive Amazon.com: Lisle 24610 Spill-Free Funnel: Automotive
pogeeboy27 is online now   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Hot weather=Limp Mode!! HELP!! Amccowan Honda Civic (2001 - 2005) 5 06-13-2016 05:59 AM
Limp mode trouble shooting Freemananana Tech / Misc 2 09-21-2015 09:01 AM
2009 Civic in limp mode - error codes jhyland Honda Civic (2006 - 2015) 1 07-27-2015 11:23 AM
2002 EX auto. RPM drop, stall, limp home mode. Video included Khmi Honda Civic (2001 - 2005) 1 06-28-2015 07:42 AM
93 civic b20/vtec setup.. check engine light problem. EgK2o09 Tech / Misc 6 12-04-2013 06:19 PM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -8. The time now is 09:14 AM.

  • Ask a Question
    Get answers from community experts
What's your question?