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Discussion Starter #1
Hi folks
After spending days researching I came up with how to tell if your Focus RS has the 'C' part number or the 'B' part number head gasket.
It appears to change in the factory sometime before July 2017. My engine code is 17G03 and I have the C gasket from factory (2500kms so far, coolant fine).
This means my engine date is 3rd July 2017 and my chassis build date is August 2017, delivered to me in November 2017 in Australia.
I'm sorry I can't be more specific about when it changed in the factory. I do not know.
Here's how to check in 2 minutes if your car has one or the other.
First, here's the two gaskets side by side. Original part on this car was already Revision B. I don't know of any revision As. The C is the latest and only update to this head gasket in Ford's parts system and is the one used on at least later 2017 and all 2018s.

0GasketCompare.jpg

BTW this is really well checked. I checked all the failure pics/posts and verified they're all B gaskets. I checked all the updated parts photos people posted that had the C part number and verified, that's the C gasket. Feel free to triple check but I spent days checking :)

OK now how do you tell which you have?
The C gasket has some material that extrudes from the top left of the gasket as shown in these photographs, outside of the interference area. It also has a little raised hole in it (is that an embossed hole? not sure the term). The B gasket has neither of those. See the general area shown in these photos , with the specific bit of gasket highlighted in the blue area:

1FindTheTab.jpg

So you can see the silver part inside the green box outside the head interference area. That will be the part you feel for. You can literally feel this flat piece of metal gasket and the embossed/raised hole in it.
If you only feel the small piece of gasket and not the longer piece, and no hole...you have a B gasket. It will be very obvious to feel the longer piece and raised hole in the C gasket.

You have to look for it here. I recommend pulling off your engine cover (it comes off the 4 round spherical ball joint clip things by pulling firmly each one). Then you can see better. Slip your hand or try to use torch/mirror (i used hand, way more reliable haha) under there and look specifically at the corner of the block/feel for it. Once you have it feel inwards a bit and you will certainly be able to feel the head gasket extruding there if you have a C. the B gasket will feel less obvious but you'll still feel that bit outside the interference area but you won't feel any raised hole and it will be clear to you which it is, if you look at the photo while feeling.

Anyway in a few mins I was able to put my mind a BIT more at ease.
I know having a C gasket is not a guarantee yet that you're fine but its still notable that beyond mid 2017 there's almost no failures and none I have read anywhere that involve the C gasket. It seems the combination of manufacturing improvements and the extra headroom from the C gasket work well.

FWIW my take is the issue is a manufacturing issue around the surfacing of the head or deck, and how that relates to the sealing requirements of this gasket type. In numerous failures the head/surface flatness is out of spec, but it might be a symptom not a cause. Either way I suspect its a cause / factor and the design of the B gasket compared to the C (between the cylinders especially) indicates margins on the B gasket are tighter so earlier cars sometimes had a worse machining/spec on the head flatness.

It's one of the only parts Ford revised since the major updates and its probably a response to seeing 'some' later models have the issue.
I hope this helps someone out - thanks to lucky phil for his comment that the C gasket should be observable on a fully assembled car as that led me into the garage to try and tell which one i had, and it was blindingly obvious when i felt the edge of the block there.

Cheers
 

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Thanks for posting this I'll be throwing my hands in the engine bay, once it cools.

I have a late 2016 engine build on my MY17... Fingers crossed.

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Discussion Starter #3
Somehow the photo of where to feel lip/edge of the HG got lost.
here it is:

2LocationOfTab.jpg

I also found the other corner on the same edge of the gasket (front/left of engine as you look at it from in front of the engine bay not in the car) you can clearly feel the sharp edge instead of the curvy edge and there's a nice big hole in the C gasket there you can spot.

however the spot above feeling for that edge as shown in the photos is the easiest. Be aware that embossed hole is actually closer to the bridge on the block than it appears, so dont panic if you feel the hole a bit closer to one side than it looks in the photo - if you can feel that nice long edge all the way to the corner of the block and the embossed hole on that lip, its the C. :)
 

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Thanks for the great post! Looking at the photos, is the front of the block at the top or bottom? Will the extra flange be on the front or rear of the engine facing the car?
 

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Discussion Starter #5
Thanks for the great post! Looking at the photos, is the front of the block at the top or bottom? Will the extra flange be on the front or rear of the engine facing the car?
sorry I couldn't work out how to update my original post showing where the lip is. but check out post #3 in the thread I show a photo of the engine bay and where you'll need to hunt under for the gasket lip.
I also found the corner opposite that (i.e. same 'end' of the engine bay, but the left corner instead of the right corner), you can feel whether you have the curvy lip on that corner with the small hole (B gasket) or the straighter edge with the large hole (C gasket). but that spots harder to find. go for the easy one first :)
 

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Please retake those photos so we can see the actual part numbers on those gaskets.
 

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Discussion Starter #7
by the way in case it helps or wasn't obvious, the gasket is shown in these images is flipped diagonally so i could compare the two from different image sources
anyway the lip highlighted, if you look at the car from in front of it, down/into the engine bay, its the bottom-right corner of the engine. i.e. the corner closest to you on the right.

i took a fair bit of time to look at block photographs, copy/paste the gasket in photoshop, and overlay it onto the block, so i could clearly spot the differences between gasket B and C, and also so i could find the spot on my car. :) if you google image search 'focus rs block' and note in images you find, the turbo is behind the engine in the engine bay closest to the firewall, you can help assure yourself on the alignment vs my photos. :)
 

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Discussion Starter #8
Please retake those photos so we can see the actual part numbers on those gaskets.
Hi!, sorry I would, but these aren't my images. they are taken from various focusRS member's posts and also from the jalopnik article which was similarly sourced. The QR code was scanned by two of the failures and verified. There's only two part numbers for the Focus RS headgasket in the Ford ICAS or whatnot ordering system, as quoted in my post, only the -B and -C variant of it.

Hope this helps, part # i found is in my 1st post,
 

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Thanks Travis. There was a new thread citing the chance that they used Mustang 2.3 Eco Boost HG's for some unlucky cars that might be the culprit. If so, makes me wonder if even if you don't have a 'C' HG, you could have the correct RS HG which might not have the flange. Just more confusion, but I certainly appreciate you sharing your findings!
 

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17F22 engine built date...so 22nd June seems to have revision C. Just checked and instead off rounded corner...nice sharp edges on the top left corner from the driver seat perspective.

Cheers
Tom

Wysłane z mojego MI 6 przy użyciu Tapatalka
 

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Hi folks
After spending days researching I came up with how to tell if your Focus RS has the 'C' part number or the 'B' part number head gasket.
It appears to change in the factory sometime before July 2017. My engine code is 17G03 and I have the C gasket from factory (2500kms so far, coolant fine).
This means my engine date is 3rd July 2017 and my chassis build date is August 2017, delivered to me in November 2017 in Australia.
I'm sorry I can't be more specific about when it changed in the factory. I do not know.
Here's how to check in 2 minutes if your car has one or the other.
First, here's the two gaskets side by side. Original part on this car was already Revision B. I don't know of any revision As. The C is the latest and only update to this head gasket in Ford's parts system and is the one used on at least later 2017 and all 2018s.

View attachment 254058

BTW this is really well checked. I checked all the failure pics/posts and verified they're all B gaskets. I checked all the updated parts photos people posted that had the C part number and verified, that's the C gasket. Feel free to triple check but I spent days checking :)

OK now how do you tell which you have?
The C gasket has some material that extrudes from the top left of the gasket as shown in these photographs, outside of the interference area. It also has a little raised hole in it (is that an embossed hole? not sure the term). The B gasket has neither of those. See the general area shown in these photos , with the specific bit of gasket highlighted in the blue area:

View attachment 254066

So you can see the silver part inside the green box outside the head interference area. That will be the part you feel for. You can literally feel this flat piece of metal gasket and the embossed/raised hole in it.
If you only feel the small piece of gasket and not the longer piece, and no hole...you have a B gasket. It will be very obvious to feel the longer piece and raised hole in the C gasket.

You have to look for it here. I recommend pulling off your engine cover (it comes off the 4 round spherical ball joint clip things by pulling firmly each one). Then you can see better. Slip your hand or try to use torch/mirror (i used hand, way more reliable haha) under there and look specifically at the corner of the block/feel for it. Once you have it feel inwards a bit and you will certainly be able to feel the head gasket extruding there if you have a C. the B gasket will feel less obvious but you'll still feel that bit outside the interference area but you won't feel any raised hole and it will be clear to you which it is, if you look at the photo while feeling.

Anyway in a few mins I was able to put my mind a BIT more at ease.
I know having a C gasket is not a guarantee yet that you're fine but its still notable that beyond mid 2017 there's almost no failures and none I have read anywhere that involve the C gasket. It seems the combination of manufacturing improvements and the extra headroom from the C gasket work well.

FWIW my take is the issue is a manufacturing issue around the surfacing of the head or deck, and how that relates to the sealing requirements of this gasket type. In numerous failures the head/surface flatness is out of spec, but it might be a symptom not a cause. Either way I suspect its a cause / factor and the design of the B gasket compared to the C (between the cylinders especially) indicates margins on the B gasket are tighter so earlier cars sometimes had a worse machining/spec on the head flatness.

It's one of the only parts Ford revised since the major updates and its probably a response to seeing 'some' later models have the issue.
I hope this helps someone out - thanks to lucky phil for his comment that the C gasket should be observable on a fully assembled car as that led me into the garage to try and tell which one i had, and it was blindingly obvious when i felt the edge of the block there.

Cheers
Super Helpful. Thank you for the hard work and time invested.


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Great info. Thanks.
I went a felt around my engine which has a date of Nov 26 2016 (car bought April 29 2017).
Seems like I have the old B head gasket. Could not feel the part protruding in the area boxed in red below. And I think i did feel the black tab with the small hole in the area in blue (like in the picture above).

InkedInkedjgvuld8lljv1q1yiyhb7_LI.jpg

Looks like the B gasket without the protuding corner section and with the two holes in between the cylinders was the original design for the engine though per the Ford Technical Service training supplement document.

Screenshot_1.jpg
 

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So is the B gasket the same as the "wrong" mustang gasket?
Thanks for the great write up Travis.
Don't think so. The B gasket seems the original design one and the C is the new design. Nothing to do with a wrong mustang part fitted as far as I can see. And the technical service training doc that I showed above for the RS even shows the old B gasket with the two holes and not one hole on the C.
Maybe the original B gasket design matches the Mustang gasket and there was never any mix up with installing parts and then they redesigned it and started using the C gasket.
 

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Is there anyway of udentifying the mustang gasket?
So the theory that the issue is related to the use of the mustang gasket is not entirely correct as a lot of the failures are actually the RS B gasket?
 

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17F22 engine built date...so 22nd June seems to have revision C. Just checked and instead off rounded corner...nice sharp edges on the top left corner from the driver seat perspective.

Cheers
Tom

Wysłane z mojego MI 6 przy użyciu Tapatalka
Top left corner facing the engine should have the sharp corner.

Ciao
 
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