EP6 125 THP engine block/head gasket replacement

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Agrg21
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EP6 125 THP engine block/head gasket replacement

Post by Agrg21 »

Hello all,

I'm new to this forum and apologies if this discussion already exists but I'm seeking advice on a particular issue I've encountered. While cleaning the surface of the engine block I noticed a small chip/crack in-between the 1st and 2nd cylinder liners (attached photo). The liners themselves look fine but not sure how far the crack or chip extends below. Also it looks like a repair has already been carried out prior to me removing the head?? Firstly, does anyone know if this would likely be cause to a head gasket failure with this defect and if so can a repair be carried out on such a small area?

If this post looks familiar, I have also posted this question on another forum. Sorry, just trying to get as many views and ideas about this...

Many thanks
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20210912_172640.jpg
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xantia_v6
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Re: EP6 125 THP engine block/head gasket replacement

Post by xantia_v6 »

The aluminium web between the cylinder pairs does not really serve any purpose, and won't cause a problem with the head gasket because the head gasket seals to the liners.

Do check that the top face of the liners are parallel and level across the engine.

Where was your previous head gasket leaking?
Agrg21
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Re: EP6 125 THP engine block/head gasket replacement

Post by Agrg21 »

xantia_v6 wrote: 14 Sep 2021, 08:16 The aluminium web between the cylinder pairs does not really serve any purpose, and won't cause a problem with the head gasket because the head gasket seals to the liners.

Do check that the top face of the liners are parallel and level across the engine.

Where was your previous head gasket leaking?
Thank you for your reply xantia_v6,

That is a relief. The liners do look parallel using a straight edge, albeit I bought this from Amazon so not sure how level it is...
My initial plan was to just do a timing chain change due to the death rattle, but I was losing coolant and had some white smoke in the exhaust with fairly high temps. The car then developed low oil pressure fault. The car was really sluggish as well with alot of injector cut offs due to knock detection. So I decided to take the head off to check for any damage, change the head gasket, clean out the intake ports, while also changing out the oil filter housing seals, oil pressure sensor, water pump and thermostat. I've also changed out the vanos oil guide seal rings on the intake cams. The intake ports were caked in carbon with chunks coming off (time for OCCs)! So that may explain the sluggishness and knocking.

I'm hoping all this work is worth it...

Thanks again,

Will probably have some more questions... :)
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Re: EP6 125 THP engine block/head gasket replacement

Post by xantia_v6 »

Just in case you overlooked it, you should also change the turbo oil feed pipe, as the originals always leak after having been removed and refitted. I bought this kit which is much better quality: http://shopping.kinugawaturbo.com/turbo ... 1-1-1.aspx, but you may find something closer to home.
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Re: EP6 125 THP engine block/head gasket replacement

Post by Agrg21 »

I was looking at getting braided lines. As you have noted, the hard lines are leaking and will definitely need to be replaced. The kits I've found in the UK are bit pricing but still shopping around

Thanks again 👍
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Re: EP6 125 THP engine block/head gasket replacement

Post by gwest »

It will be interesting to see if changing the oil seals on the intake camshaft fixes the low oil pressure problem. If it is an old motor it may well have had camshaft chain tensioner problems and it would be good to verify that there are no plastic bits from the chain guides caught in the oil pump strainer. How many miles has the engine done?
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Re: EP6 125 THP engine block/head gasket replacement

Post by Agrg21 »

The engine hasn't done that many miles, not for its age, around 54k. I'll keep you all posted on how this "project" goes...
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Re: EP6 125 THP engine block/head gasket replacement

Post by xantia_v6 »

I have read elsewhere that low oil pressure can be caused by a fractured oil pump body, caused by debris from a broken timing chain tensioner getting caught in the chain and going around the oil pump sprocket. If the history of your engine allows this possibility, then keep it in mind.
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Re: EP6 125 THP engine block/head gasket replacement

Post by Agrg21 »

xantia_v6 wrote: 16 Sep 2021, 18:55 I have read elsewhere that low oil pressure can be caused by a fractured oil pump body, caused by debris from a broken timing chain tensioner getting caught in the chain and going around the oil pump sprocket. If the history of your engine allows this possibility, then keep it in mind.
Thanks, will keep this in mind.
Finally got a chance to "fully clean" the mating surfaces. I think I may have commited a faux Pas by using sand paper. I used only p1000 grit and above. I couldn't get all the gasket material off but not sure if that's because there is corrosion and pitting at the gasket joining areas.. The block and head are level enough though...
See attached and let me know what you guys think, do you think it still needs more work?
Attachments
20210918_154945.jpg
20210918_162130.jpg
20210918_162136.jpg
20210918_162145.jpg
20210918_162156.jpg
20210918_162202.jpg
20210918_175550.jpg
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Re: EP6 125 THP engine block/head gasket replacement

Post by xantia_v6 »

From this distance it looks OK.

Good luck.
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Re: EP6 125 THP engine block/head gasket replacement

Post by Dormouse »

As long as you have a flat surface and have cleaned all the debris as thoroughly as possible. Water jackets are ok but pay special attention to areas where oil goes and you should be fine.
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