Cylinder 4 running hot

So the bent dipstick issue is sorted! Onto the next issue lol.

Basically, my cylinder 4 is running very hot, you can see that the GizFab 4-2-1 manifold is turning 'blue hot' on the 4th cylinder. This blueing has been getting progressively worse. The photo shows how it is currently. The manifold went in on the 10th March, so this is how much it has blued in just under a month. After parking up and coming back to the car after about 30 min, I could easily physically feel the difference in temp betweek cylinder 4 and the other headers. Interestingly, cyl 1 felt the coolest, cyl 2 a little hotter, then cyl 3, and then cyl 4 MUCH HOTTER.

IMG_1613 - Copy.JPG


Been advised it could be a faulty injector? thus causing cylinder 4 to run lean? thoughts?
 
As Frank says, exhaust header #4 will be getting less airflow cooling from the grill compared to the others due to the obstructing CAI duct but it's also getting hotter air from behind the rad

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As Frank says, exhaust header #4 will be getting less airflow cooling from the grill compared to the others due to the obstructing CAI duct but it's also getting hotter air from behind the rad

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Thank you for your knowledge Paul!
I have removed the intake pipe.

Drove the car for a bit. After coming home and letting it cool for around 20 min, I went outside and physically touched the headers, they all seemed to be of equal temp now.

Thanks.
 
I'm more surprised the plastic pipe hasn't melted if so close to the manifold.

Yes it had melted a little. Its a steel ring reinforced pipe, so the outer black plastic had melted but the metal rings didnt. But it only melted at the point where it was actually touching the manifold.
 
Yes it had melted a little. Its a steel ring reinforced pipe, so the outer black plastic had melted but the metal rings didnt. But it only melted at the point where it was actually touching the manifold.
Perhaps wrap it in tin foil next time to Insulate and reflect the infrared heat away from the plastic duct?

In terms of extra heat from the rad, how bout a simple dividing plate between the rad & exhaust to keep em separate?

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Wont a dividing plate make the manifold hotter?

Would it?
I would think the heat from the rad will stay away from the manifold. Otherwise its an additive effect of the heat from the rad plus the heat from the manifold.

If you think I am wrong, please let me know, I am always all ears to learn! :)
 
Would it?
I would think the heat from the rad will stay away from the manifold. Otherwise its an additive effect of the heat from the rad plus the heat from the manifold.

If you think I am wrong, please let me know, I am always all ears to learn! :)
Yup by shielding the hot radiator air to flow away from the manifold, ur left with cool air coming from the front grill to blow onto the manifold to cool it abit.

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Why do we care how hot the manifold gets? I can understand the original question as it might indicate a fault but it's not like the manifold is going to melt.
The heat shielding I can see as useful to keep heat out of the inlet duct or stop the exhaust heating up the back of the radiator or generally keeping under bonnet temperature lower but I can't see it aiding cooling the exhaust, but I may not understand what type of dividing plate Paul means.
On an aesthetic note I wouldn't want to cover up your pretty gizfab manifold.
 
Why do we care how hot the manifold gets? I can understand the original question as it might indicate a fault but it's not like the manifold is going to melt.
The heat shielding I can see as useful to keep heat out of the inlet duct or stop the exhaust heating up the back of the radiator or generally keeping under bonnet temperature lower but I can't see it aiding cooling the exhaust, but I may not understand what type of dividing plate Paul means.
On an aesthetic note I wouldn't want to cover up your pretty gizfab manifold.

Yes you are right its not so much the concern the manifold will melt, but more the concern that cylinder 4 is running very hot which could cause internal damage to the cylinder.

And regarding a dividing plate, I think something like what Audi guys use for their cold air intakes should be sufficient. Just a plate to separate the temp difference. For example, like on this BMW, 2 plates have been used to keep the region around the air filter cold.

And yes aesthetically, I prefer the blue purple manifold lol!

MMAI-E46-01BK_6_3.png
 
Air off the radiator will be around 90°C, the manifold temp will be up at over 600°C, the radiator as it stand will keep the manifold cooler. However, the heat from the manifold will fill the engine bay, so swings and roundabouts. Lagging the manifold to get the heat under the car maybe better overall.

But regarding the divider, if the belief is that the plastic (coated) pipe is causing the no.4 header to get hot and discolour, then blocking all airflow to them from the radiator will make them all the same. Unless you have some additional ducting to allow cool air in to the manifold. You'll also restict the airflow away from the radiator (depending how you do it), as the air must now find a way out since it cant go straight back.
 
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You can have a distance thermometer (the word has escaped me) relatively cheap off ebay, it might have trouble with the manifold being shiny but it might get you a read on the temperature. they're about £20

Run it up to temperature by driving it around with the way it is now and get a reading on each cylinder, then remove the ducting and see if it makes a difference

They're useful to have anyway, I found out that my timing was off only because my airbox was sitting at 60 celcius lol
 
You can have a distance thermometer (the word has escaped me) relatively cheap off ebay, it might have trouble with the manifold being shiny but it might get you a read on the temperature. they're about £20

Run it up to temperature by driving it around with the way it is now and get a reading on each cylinder, then remove the ducting and see if it makes a difference

They're useful to have anyway, I found out that my timing was off only because my airbox was sitting at 60 celcius lol

A infrared thermometer
 
Comparing spark plug colour should tell you (roughly) about injector performance. I think that four nice looking plugs will ensure you it is not fuel related.

Old plugs looked okay tbh. Plug 2 looked a bit on the overfueling side, others looked okay. This points more to the fact that it’s not a faulty injector and more what Frank initially suggested which is the intake pipe blocks airflow to cylinder 4.

New plugs are going in soon anyway!
 
So the bent dipstick issue is sorted! Onto the next issue lol.

Basically, my cylinder 4 is running very hot, you can see that the GizFab 4-2-1 manifold is turning 'blue hot' on the 4th cylinder. This blueing has been getting progressively worse. The photo shows how it is currently. The manifold went in on the 10th March, so this is how much it has blued in just under a month. After parking up and coming back to the car after about 30 min, I could easily physically feel the difference in temp betweek cylinder 4 and the other headers. Interestingly, cyl 1 felt the coolest, cyl 2 a little hotter, then cyl 3, and then cyl 4 MUCH HOTTER.

View attachment 68518

Been advised it could be a faulty injector? thus causing cylinder 4 to run lean? thoughts?

Your improvised intake hose appears to be almost twice as long as the original K11 matched balanced & dynamic harmonic resonant frequency damped air intake assembly that was also OEM positioned at the the battery near side at a significantly less low level at its intake for cooler less turbulent air pickup with less lift energy losses required.

In short, Frank was right on the money as always. :cool: Cool air man.

good luck.
 
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