Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

Glowing Red Exhaust Manifold Please Help!!!!

 
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions
View previous topic :: View next topic  
Author Message
CalGuy  



Joined: 17 Oct 2009
Posts: 56
Location: Woodside, CA

PostPosted: Wed Nov 25, 2009 4:11 pm    Post subject: Glowing Red Exhaust Manifold Please Help!!!! Reply with quote

Hi everyone,

I have a 1980 924 (non turbo) and am combating two evil woes: 1) an overheating problem during extremely warm weather and 2) a red/orange glowing exhaust manifold.

I think I am close to a resolution for problem # 1). I am installing an all aluminum custom radiator to replace the OEM one and doing a full through flush of the entire cooling system with distilled water and doing it twice! I will be done with that tomorrow and drop in the new radiator as well so hopefully that will take care of the overheating problem I have during extremely hot weather (won't now for sure though until I have it on the road on a warm day which will be a few months from now

But for problem #2) I don't know what else to do! I ran the car through an exhaust analyzer and found that it was a little too rich so I had the fuel mixture and ignition timing adjusted and got that tuned on the dot. But I notice the manifold still glows orange/red after the car is idling for about 5 or less minutes. Also the engine bay is always hot, it's been that way since the day I bought it from the first owner. In the course of having the car I have changed the following:

Spark plugs, wire, cap and rotor
Fuel Injectors
Timing Belt and checked the timing, it's spot on
Water Pump
Thermostat (changed to the one that opens at 84deg)
Fan Switch on Radiator (changed to the one that opens at the lower temp rather than the original higher temp)
All Radiator Hoses
Overflow Expansion Tank
Took out the Catalytic Converter and put in a straight pipe
Exhaust

I'm not sure what else to do! I run 91 Octane from 76 or Chevron and read on some of the posts that the higher octane may be a contributor to the red glow but somehow I don't think it would make a big difference especially if the car isn't running rich (since I already had both the ignition timing and fuel mixture checked and had them adjusted).

Also, it's not a Turbo so I don't think the glowing exhaust manifold should be that color. And lastly, it does feel hot when I stand on that side of the car on the outside (passenger side). It's always been that way since the day I got it from the first owner. Not sure though why?

Any insight and help is greatly appreciated before I contemplate driving it into a pond!!!

Thanks in advance.
_________________
-CalGuy
1980 924
1992 968 (Newest edition dubbed 1BAD968)
2001 Range Rover HSE
Back to top
View user's profile Send private message
968rz  



Joined: 21 Aug 2006
Posts: 537
Location: S. E. Wisconsin

PostPosted: Wed Nov 25, 2009 5:25 pm    Post subject: Reply with quote

A red hot header could be a lean condition or plugged exhaust. Could also cause it to run hot.
_________________
Rick
79 924 coupe Petrol Blue 3spd auto (wife's DD)
93 968 coupe Amazon Green 4spd Tip (my DD)
02 Trailblazer Red 5spd auto (wife's winter car)
06 Jetta sedan Graphite Blue 6spd Tip (my winter car)
Back to top
View user's profile Send private message Send e-mail
Rich H  



Joined: 10 Jun 2007
Posts: 2665
Location: Preston, Lancs, UK

PostPosted: Wed Nov 25, 2009 7:08 pm    Post subject: Reply with quote

Very odd on an N/A. If you haev secondary burning you might be very rich and then the secondary burning is giving a false reading on the gas tester. Try turning the mixture down see how low you can go without the car stalling. Note where you started from so you can put if back if you have to.

Rich
_________________
1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec
Back to top
View user's profile Send private message
daniel  



Joined: 18 Jun 2009
Posts: 610
Location: Sydney, Australia

PostPosted: Thu Nov 26, 2009 8:35 am    Post subject: Reply with quote

Three things come to mind:
1) Exhaust leak causing combustion inside the pipes
2) Lean mixture/advanced ignition timing, who checked it? sure they got it right?
3) blocked exhaust, even partially blocked.

Best of luck
_________________
Over the top of skyline, total brake failure.... hit the wall at over 200 kp/h at the dipper, so anyone who has to brake for the esses is a pussy.
1977.5 Race Car, CAMS Group S Spec
1989 944 Cabriolet
Back to top
View user's profile Send private message
Min  



Joined: 04 Nov 2002
Posts: 2365
Location: Vernon, British Columbia, Canada

PostPosted: Thu Nov 26, 2009 2:30 pm    Post subject: Reply with quote

I know that retarded ignition timing will cause your manifold to turn red. This happens because the exhaust valve opens while gas is still burning in your combustion chamber. A partially blocked exhaust will also cause this problem as Daniel mentioned.

First thing I would do, is investigate your exhaust stream, check your catalytic converter for breakdown. Also, check your muffler for broken baffles. Either of those conditions could cause a plugged exhaust.

Second thing I would do, is start to re-investigate your timing. Check your cam timing, insure that the correct marks were used when it was checked the first time around. Make sure that top dead center is in fact top dead center. Next, take apart your ignition distributor and have a look, perhaps something is wrong with it. Is the vacuum correctly connected to it? If you have it hooked up incorrectly, your ignition timing may not properly be advancing throughout the range.

Min
_________________
Custom means it didn't come from a box.
1980 n/a with EDIS and Megasquirt II Injection. 7 different colors and counting.
Back to top
View user's profile Send private message Send e-mail AIM Address Yahoo Messenger MSN Messenger
CalGuy  



Joined: 17 Oct 2009
Posts: 56
Location: Woodside, CA

PostPosted: Sat Nov 28, 2009 6:47 pm    Post subject: Reply with quote

Thanks for the replies and advice everyone!

I was hoping to have the car smoged checked today but I didn't have a chance. Hopefully tomorrow I can go do that and make sure that the stats are running ok on the exhaust analyzer. I'll also double check the exhaust system. I changed the muffler a few years ago (I haven't driven any more than 5,000 miles on the car since the installation) so I don't think it's clogged but you never know!

I've also added the cats back on for the smog so I'll check if it's still glowing red. My thoughts were if I took out the cats that it would not be glowing red anymore but I was wrong. (The car did run smoother though!)

I'll keep you posted on my findings...

Thanks
_________________
-CalGuy
1980 924
1992 968 (Newest edition dubbed 1BAD968)
2001 Range Rover HSE
Back to top
View user's profile Send private message
924red77  



Joined: 07 Feb 2018
Posts: 1
Location: San Jose

PostPosted: Wed Feb 07, 2018 9:00 am    Post subject: The Glowing Red Manifold Mystery? Reply with quote

What ever happened with this old post, did you ever figure out
the cause of the red hot manifold? Blocked exhaust or too lean?
Maybe too old of a post but thanks.
Back to top
View user's profile Send private message
Fasteddie313  



Joined: 29 Sep 2013
Posts: 1459
Location: Not Detriot - NMI

PostPosted: Wed Feb 07, 2018 9:59 am    Post subject: Reply with quote

Probably too lean, if you have lambda tune with a dwell meter, frequency valve duty cycle, not to some random AFR you are trying to accomplish..

Or, unplug your O2 sensor, tune idle to stioch, andplug your O2 back in, or not..

Dewll method on fully functioning lambda with all of your CIS pressures in spec is the best and right way to do it..
_________________
1980 931S LSD FMIC hobby - 01 RS25 coupe - 95 M3 coupe - 06 X5
Back to top
View user's profile Send private message Yahoo Messenger
RC  



Joined: 25 Mar 2007
Posts: 2624
Location: Australia

PostPosted: Thu Feb 08, 2018 12:25 am    Post subject: Reply with quote

Or ignition timing too retarded. Does it also feel more gutless that it should be? Does you car have a cat?
Check the initial timing and mechanical timing advance with a timing light. Maybe temporarily disconnect the USA timing retard hoses, use good grade fuel and try more advance.
_________________
World`s quickest 924 2L slushbox

Allan @ DTA wrote:
I have no issue with superchargers, they are for guys who want to drive a car rather than talk about horsepower with their baseball cap on backwards
Back to top
View user's profile Send private message
Qik Nip  



Joined: 16 Jan 2015
Posts: 115
Location: Kentucky

PostPosted: Tue Mar 27, 2018 6:41 am    Post subject: Reply with quote

I had a '76 NA years ago that exhibited a glowing exhaust manifold and after lots of worry and research, determined it was apparently normal! I drove the car until it had 148,000 trouble free miles on the odometer - all of them with the orange glow ... and then sold it to a guy who put another 50K on it before he sold it!
_________________
'79 NA 924 Land Speed Car
Bonneville G/CPRO record holder @ 145.632 MPH
'96 LT4 C4 daily driver
Great Lakes SCCA SM points champion '09,'10,'11
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions All times are GMT + 11 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group