Is it possible to change the main chain guides/pads without splitting the block?

As per the title. Is this achievable if I drop the engine? If not I won't drop the engine. I'll just change the cam chain pads.

So your car is a 996 with a 2.5L boxster engine in it?

No, it's a 986 with a Boxster engine. Sorry for being unclear.

I'm sure you don't have to on a 3.6L. I think your 2.5L should be the same. You may want to check with folks in the Boxster forum and also on renntech.org...very helpful Boxster experts there.

Boxster or 911?im confused

Boxster. I thought the engine cases were almost identical so I thought this was a good place to ask.

Quotes source post: 13268418

It was definitely worth a try. The. 996 forum has some of the best engine "experts" of any forum around. We are really lucky.

Yes you can the tensioner blades are located inside the chain boxes accessed by removing the heads, you may need to remove coolant housing with oil pump to get to the securing bolts on the front of the engine, you can do the vario cam pads in the heads too they get the most worn, why are you wanting to do this?

My cam deviation is way out of spec and I've ordered the pads for the tensioners. Then it struck me that perhaps other pads are worn in a similar way and that I should probably change as many of the pads as possible when I'm at it. I just realized I should have asked "without removing more than the valve covers" because I'm not going to remove the heads.

I don't see why you need to remove the heads. The blades are held in place by either one or two bolts, which are all accessible fron the engine case, on the flywheel side and the main pump side. Like Noz said, one of the bolts is blocked by the front coolant console (where the main oil pump mounts onto), which needs to be removed or at least undone and seperarted from the engne case.

Thank you for wanting to help. The way I read Noz' post was that the heads have to come off to be able to pull out the blades. Is this recommended for maintenace, or would you wait for when it's time for a complete rebuild? On the 996, would you drop the engine for this, or would you be able to do this with the engine in the car?

Drop the engine. If I remember right, the 1-3 chainrail bolt is behind flywheel.

I'm removing the flywheel to inspect the IMSB anyway, but on the boxster that is easy to do with the engine in the car. I guess once the transmission is of It's not too much work to drop the engine. It will be much easier to keep contaminants out with the engine out of the car. I'm clutching at straws 'cause I would like to wait for the off-season before I drop the engine. This is a dedicated track-day car so I need to ensure the engine doesn't blow up during the season though.

Ahsai is probably right I did a full rebuild on my engine so they went in before the heads but you will have to at least take the cams and vario tensioner off to access the top of the chain box to get them out but you can do the vario tensioner pads while your there they get the most wear mine had deep grooves but the rest were not too bad light marks, I'm not sure which pads cause cam deviation the most Ahsai do you have any idea??

Quotes source post: 13272926

I believe the variocam pads are the ones most responsible for cam deviations. OP, I would suggest removing the engine for this work and also check out this thread. Someone else posted this today helping another poster. https://rennlist.com/forums/996-forum/615351-996-ims-timing-chain-guide-transmission-pinion-bearing-and-misc-items-diy-project.html

I thought it was the vario pads but didn't want to dive in coz I wasn't sure!! On my rebuild all chain rails were good, slight wear on the rails were the tensioners apply force to them but overall very good, except the vario pads they were a mess, the plastic seems too hard and brittle and should be more like nylon type material in my opinion, someone should re design these like Jake maybe ??

Thanks everyone. I have decided to try to leave the enigne in out of fear of the take-it-out-and-never-put-it-back-in-due-to-the-WYIT-syndrome im diagnosed with I'll make up my mind once I have the transmission off, but theres a lot of hoses and connectors involved. I'll check the IMSB, do the cam chain tensioner pads install the deep sump and leave it at that. I'll happily drive another season after learning that the main pads normally don't wear as bad. I will then pull the engine at the end of the season and do a more thorough job, or even a 3.4L swap.