Hot Manifold

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Mon, 07/09/2015 - 22:01
rkl786
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Over the weekend I replaced the fuel filter, air filter, and fuel pump on my 1991 463 230ge G wagen. Today when I took it for a drive, I notice a smell coming from my Gwagen. The smell came from the rubber mat on the passenger side due to the muffler underneath running very hot. I open the hood as well and notice that a small area of the manifold was bright red. I think the issue might be due to the fuel pump, but what else should I check as well? Thank you
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Tue, 08/09/2015 - 01:26
#1
scouse g
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Re: Hot Manifold
A blocked exhaust but its normally the cat is blocked or the silencer has collapsed, but i'm not sure your car has a cat ?
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Tue, 08/09/2015 - 13:56
#2
Pistonhead
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Re: Hot Manifold

Hello,

You do not mention how you drove (Hard driving) before this smell occurred.

I do not think a blocked exhaust could cause a hot spot to this extent; firstly to have a hot spot one needs a free flowing exhaust gas and have excess burning fuel, if you did not experience any power loss then there is no possibility of blocked exhaust. The fuel pump may have nothing to do with this directly. Did you check/readjust the fuel mixture after fuel pump replacement. Ordinarily one would not have to check this but in this case there may be one more item eliminated in a check list .

Is your exhaust system original or after market? The argument for aftermarket exhaust could be due to a thinner gauge of metal used in the construction of the system.

The exhaust manifold only reaches a cherry red colour when driven hard at full throttle. You could be lacking in heat shielding around the exhaust.

I am not up to speed with the W463 230GE engine. Is it the M102/201 engine? I can only conjecture that the ignition timing and, or fuel mixture is wrong (lean) at high revs. The most probable scenario is late ignition timing but with that a loss of power would be experienced.

I am not full knowledgeable on the EGR valve, if you have one on your engine, I know this much that the EGR valve is allowed to recirculate a small sample of exhaust gas within certain temperatures; I am thinking if the sensor controlling the EGR valve is faulty it could mean gas circulation at an untimely point causing lean burning, hence the hot spot.

At what area on the manifold is this hot spot?

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Tue, 08/09/2015 - 19:47
#3
rkl786
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Re: Hot Manifold
The 463 230GE engine is the M102. The exhaust system is after market. Before I bought the Gwagen the dealer had replaced the exhaust around January this year. As for driving, I really notice the smell when going up a hill. Later on when testing, again when going down and up a hill. I am thinking the problem might be the fuel and Gwagen running rich/lean and the ignition timing. I attached a photo of the general area of the hot spot. Let me know if that helps.
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Tue, 08/09/2015 - 22:19
#4
scouse g
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Re: Hot Manifold
Changing the fuel pump won't change ur fuel mixture that ur running but dont forget ur little 2.3motor is pushing 2.3ton of metal that is aerodynamic as a barn door! Its not unusual to see a white manifold
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Fri, 11/09/2015 - 21:46
#5
Arnie
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Re: Hot Manifold

did you replace the fuel-pump like for like? there are high-pressure pumps available, which may produce too much pressure. If your manifold is red-hot, there may be an over-fueling issue. Check the condition of the spark-plugs to see if they look too sooty.

 

 

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Sat, 12/09/2015 - 09:34
#6
ChrisG
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Re: Hot Manifold
Most likely timing issue. Probably been out for some time but disguised by faulty fuel pump / blocked air filter? What colour are the spark plugs??
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