Camshaft caps tightening sequence (Peugeot 406 1.8 16V)

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LFY
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Camshaft caps tightening sequence (Peugeot 406 1.8 16V)

Unread post by LFY »

Hi everyone.

I'm going to replace my lifters so I need to remove camshaft retaining caps.

My car is a Peugeot 406 1.8 16V petrol (XU7JP4 LFY).

I was reading Haynes manual and found the following tightening sequence for intake and exhaust sides.

Image

What I don't understand from the above picture is that it doesn't state clearly which one is the intake and which one is the exhaust side.

This is my engine view from front:

Image


The following is a sample image of the cylinder head of this engine. I marked the bolts based on what I understood from the Haynes manual:

Image


Please tell me if my understanding of the sequence and camshaft sides (In & Ex sides) is correct or not?

Another thing that seems weird to me is the sequence of the bolts. I have never seen such a tightening sequence for camshaft caps in other vehicles. Is that sequence normal?
In most cars I have seen the sequence starts from inside (the middle fasteners) with spiral pattern expanding outwards but this is not the case in this car.

Please help me to avoid confusion.
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moizeau
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Re: Camshaft caps tightening sequence (Peugeot 406 1.8 16V)

Unread post by moizeau »

I don't know the engine but those cam caps look individual parts, i.e. you have 12 in all. The sequence suggests you tight one side then the other. This would stop the cam from snagging if there was any play. I'm basing my knowledge on old motorbikes. I'm not sure if the cam caps are line bored in situ like they are on old Kwacks but even if not I would mark each one, and it's orientation, and make sure they go back in the same place facing the same way. Even if they're not line bored it would still help regarding current wear. One other thing to consider is the valves pushing up on the lobes, therefore trying to lift the cams out of the head. Depending how long the cam cap bolts are, as in thread available to pull the cam back down, be careful of stripping the head threads. It may be worth doing the sequence in 3 of 4 stages to even the load on the threads.
Pete
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LFY
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Re: Camshaft caps tightening sequence (Peugeot 406 1.8 16V)

Unread post by LFY »

moizeau wrote: 14 Jan 2024, 13:33 I don't know the engine but those cam caps look individual parts, i.e. you have 12 in all. The sequence suggests you tight one side then the other. This would stop the cam from snagging if there was any play. I'm basing my knowledge on old motorbikes. I'm not sure if the cam caps are line bored in situ like they are on old Kwacks but even if not I would mark each one, and it's orientation, and make sure they go back in the same place facing the same way. Even if they're not line bored it would still help regarding current wear. One other thing to consider is the valves pushing up on the lobes, therefore trying to lift the cams out of the head. Depending how long the cam cap bolts are, as in thread available to pull the cam back down, be careful of stripping the head threads. It may be worth doing the sequence in 3 of 4 stages to even the load on the threads.
Thanks for your help.
No, this engine doesn't have individual caps, it has two single-piece camshaft caps which makes it easier to install and remove them because I don't need to worry about orientation. They can only be installed in one way.