Where to get new exhaust manifolds - 2002 L18???

[prostar205]

Anyone know where to get new exhaust manifolds for a 2002 L18? My starboard side manifold has a leak. Nice thing is once it get up to temperature, the leak stops. Probably replace both manifolds at the end of the season. I see no reason to spend the money now and take a weekend replacing them.

Thanks.

[Lars]

Do you have a picture? Are they the indmar etc manifolds? Can't remember what the big blocks came with.

[Shaun R]

Manifolds leaking on the outside is one thing, but if the inner wall starts to leak you will end up with water in your oil and a trashed motor. Keep that in mind if you decide to run them for another year and check your oil regularly.

[gweaver]

You'd have to compare photos and diagrams, but I found 3 potential sources:
InboardOnline This is an Indmar part, it should be a direct replacement part.

MarineEngine Note- these are a Mercruiser part, and while the manifold should bolt up to the block just fine, your existing exhaust riser might not match up.

MarineEngineParts These folks have a couple of options, it looks like. Crusader parts, but should be a replacement except for the color. Note that on this page, the first two parts are identical except one is drilled for 3/8" mounting bolts, the other is drilled for 8mm bolts.

FWIW, Volvo used the same 8.1l block in some of their applications, so the Volvo manifold might fit as well, potentially giving you a few more options for sourcing and pricing.

G

[prostar205]

You'd have to compare photos and diagrams, but I found 3 potential sources:
InboardOnline This is an Indmar part, it should be a direct replacement part.

G

Those are them. Also just found them at Michigan MotorZ but they are out of stock. It appears the Port and Starboard are identical. Need to go down to the boat and verify.

Thanks for the help. I probably should do this sooner than later as pointed out by Shaun R.

[prostar205]

Do you have a picture? Are they the indmar etc manifolds? Can't remember what the big blocks came with.

They look like the ones in these pictures.

[prostar205]

I took the manifolds off yesterday (surprisingly it only took an hour or so to get both of them off) and it doesn't appear they are cracked. The water that I observed was coming from the risers on the inside rear area - the toughest bolt to get tight. However, when I took the manifolds off I noticed there were no gaskets between the exhaust manifolds and the heads. My guess is that's how they came from the factor.

I am going to have the manifolds pressure tested and cleaned up before putting them back on. Give them a fresh coat of paint, get manifold to head gaskets and new riser gaskets.

Lastly, take a look at the exhaust chambers. Looks like a lot of carbon build up. Should I be concerned? Engine has 670 hours on it and it's a 2002.

[mikeg205]

man she runs rich.. for riser installation cut an allen wrench and then you can use a ratcheting box end wrench - sooo much easier

[gweaver]

You might try running a can or three of SeaFoam through your tank. It's supposed to help remove some of the carbon buildup in engines. Not sure what the mix ratio is, but I tend to overdo it. If it says 1 ounce for 10 gallons, I'll do 1.5 oz. Try to do it when you're lower on fuel too.

G

[dodwellleung]

2008 X45 Manifold Riser - water jetting out from a hole on upper manifold or riser ?

They look like the ones in these pictures.

Hi all,
This is my first time to use this forum for help. The subject boat is Mastercraft X45 made in August 2008 and it is being used in Hong Kong (salt water) at a temperature much higher than freezing point.

As it can be seen from the photos and videos attached that water is jetting out from a hole on the manifold (or riser if it is correct). There is no hole on the port side manifold! Do anyone know why is there a hole on the manifold as shown in the pictures and video? I have tried to search for an answer from Youtube videos and there are none indicating the same problem but I have learnt that it maybe called a Freeze Plug???

Do anyone know how to fix it?

Your assistance is highly appreciated.

Regards

Dodwell

[prostar205]

Anyone replace their stock aluminum exhaust manifolds on the L18 (8.1L) engine with cast iron manifolds and elbows? Inboard Online sells the complete cast iron set for about the same price as the replacement aluminum manifolds. To install the cast iron version, there needs to be some "trimming to fit" activity. Not sure I want to take that on. They (Inboard Online) also told me the OEM Indmar aluminum manifolds are prone to cracking between the 2 middle cylinders. Both of mine have vertical cracks between cylinders 3 and 5 on the port side and between 4 and 6 on the starboard side. Evidently, vertical cracks indicate heat cycle issues and not freeze issues. Freeze cracks are usually horizontal. Thoughts???

[lakedrum03]

I wonder what the "trim to fit" means. If it trimming the outlet length, then that should be easy. If its port matching, then that could be an issue. From outside looking in, the products should be similar enough that you could swap them out, but others here probably know better.

[RDahler]

Looks like a Bullet hole to me maybe a 223 round.