Notices
Series I Tech Garage The place to discuss anything technical about the RX-8 that doesn't fit into any of the categories below.

Carbon Buildup

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 12-16-2009, 10:20 AM
  #1  
Registered User
Thread Starter
 
SweetBlue04's Avatar
 
Join Date: Feb 2009
Location: Pataskala, Ohio
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
Need Help with Carbon Buildup

Hey guys/gals. Just back to reading some threads. I had the intake manifold valve cleaned last November from the carbon buildup. My check engine light has come on a few times since then and I took it to Advance Auto for the code, but was able to make the light go out after some hard driving. Unfortunately, it's back on again and the cold temps in Ohio is making it hard to get the engine hot enough to burn it off. Since I was quoted a cost of over $2000 to get it cleaned, I'm trying to avoid that. Seems to me that there should be a recall to fix this. Anyway, I've read some of the threads giving instructions to clean it (thanks Jon for the video) but not sure my husband will be willing to do this. I've seen some threads mentioning Seafoam, but not sure what that is. My car's a 2004 manual with over 80,000 miles. I'm not experiencing any performance issues (and hope I won't) but want to find a way to avoid the buildup.

As a side note, I'm wondering if the automatic transmissions are having this problem. How would they keep the RPM's high enough to burn it off?

Can anyone tell me what the Seafoam is and how to use it? I love driving this car and would like to keep it for another five years. Any other tips would be appreciated.

Last edited by SweetBlue04; 12-16-2009 at 10:38 AM.
Old 12-16-2009, 11:00 AM
  #2  
Registered Zoom Zoomer
iTrader: (2)
 
Huey52's Avatar
 
Join Date: Apr 2006
Location: New England
Posts: 4,089
Likes: 0
Received 6 Likes on 6 Posts
Seafoam is a decarbing liquid/spray. It was historically more used for nautical outboard motors (hence the name) but has become the preferred decarbing spray for automotives as well. Mazda has their own spray which is similar in formulation. You can follow the Mazda decarbing procedure for significant carbonation, or use in the gas tank as a preventive measure.

In an automatic you can use the paddle shifters to hold the transmission in a lower gear to facilitate higher rev's, noting that it still won't rev as high as a manual trans, but high enough.

I'm sure in your reading here you've seen "a redline a day keeps the carbon away" and it really does help. Periodic additions of a fuel system cleaner to the gas tank, like Lucas or STP or aforementioned Seafoam, are also helpful as is use of a quality gasoline that has added detergents, e.g. Mobil and Shell. Winter gasolines in our colder climes tend to be 'richer' as well.

Additionally ensure that your ignition system is operating properly. A lot of carbon comes from lack of proper spark (caused by worn sparkplugs, coils, 'plug cables and even low output battery/alternator).

You may also want to get an engine compression check done now to baseline your vehicle and to use to compare against in the future.
Attached Files
File Type: pdf
RX8 Compression Test.pdf (154.8 KB, 353 views)

Last edited by Huey52; 12-16-2009 at 11:15 AM.
Old 12-16-2009, 11:14 AM
  #3  
Boosted Kiwi
iTrader: (2)
 
Brettus's Avatar
 
Join Date: Apr 2006
Location: Y-cat-o NZ
Posts: 20,525
Received 1,492 Likes on 840 Posts
Seafoam will not clean out your intake - that seems to be what you are concerned about .

Best way to stop that gunking up is to fit a catch can .
Old 12-17-2009, 07:52 AM
  #4  
Registered User
Thread Starter
 
SweetBlue04's Avatar
 
Join Date: Feb 2009
Location: Pataskala, Ohio
Posts: 11
Likes: 0
Received 0 Likes on 0 Posts
Thanks for the info! I'll pass it on to hubby and see what he can do. This is only thing I've had problems with in the five years I've owned the car and probably wouldn't be dealing with this now if I had been told to keep the RPMs up. I was using the higher gears to save on gas and do a lot of highway driving.
Old 12-17-2009, 01:57 PM
  #5  
Lubricious
 
Nubo's Avatar
 
Join Date: Oct 2003
Location: SF Bay Area, California
Posts: 3,425
Likes: 0
Received 4 Likes on 4 Posts
Originally Posted by SweetBlue04
Thanks for the info! I'll pass it on to hubby and see what he can do. This is only thing I've had problems with in the five years I've owned the car and probably wouldn't be dealing with this now if I had been told to keep the RPMs up. I was using the higher gears to save on gas and do a lot of highway driving.
You don't have to spend long periods of time at high rpm. It's the opening and closing of the valve that keeps the stickies away.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Carbon8
RX-8's For Sale/Wanted
42
02-27-2020 08:39 AM
Trancemission
RX-8 Multimedia/Photo Gallery
46
12-02-2015 07:26 PM
GK1707
RX-8 Parts For Sale/Wanted
0
09-27-2015 07:33 PM
RAE008
New Member Forum
6
09-19-2015 02:24 PM
RAE008
New Member Forum
8
09-12-2015 09:08 PM



You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Carbon Buildup



All times are GMT -5. The time now is 09:27 PM.