PDA

View Full Version : Bad Valves


dmayer84
10-26-2011, 01:14 PM
I know I havent been around much recently but I ran into an issue with my Predator engine and was wondering if anyone else has run into the same thing.

Currently have 175 hours on my '04 x10, bought it in 06 with 20 hours. Towards the end of the season this year we started having the check engine come on and a very rough idle. Did a compression test on it and #7 was at 40 psi and #4 was at 140, the rest were all about 170. Took the heads off and brought them to a local shop and all the valves are going bad, specifically the cylinders listed.

Is this a common issue with this engine?

We replaced them all with stainless valves at the reccomendation of the shop, just cant believe that they are going bad after just 170 hours.

JimN
10-26-2011, 02:15 PM
I know I havent been around much recently but I ran into an issue with my Predator engine and was wondering if anyone else has run into the same thing.

Currently have 175 hours on my '04 x10, bought it in 06 with 20 hours. Towards the end of the season this year we started having the check engine come on and a very rough idle. Did a compression test on it and #7 was at 40 psi and #4 was at 140, the rest were all about 170. Took the heads off and brought them to a local shop and all the valves are going bad, specifically the cylinders listed.

Is this a common issue with this engine?

We replaced them all with stainless valves at the reccomendation of the shop, just cant believe that they are going bad after just 170 hours.

Could be running lean- did the valves look round? Can you post photos of them?

dmayer84
10-27-2011, 09:59 AM
The shop is saving the old valves for me. From what he explained the valves were cupping.

JimN
10-27-2011, 10:50 AM
The shop is saving the old valves for me. From what he explained the valves were cupping.

Make sure the ECT is replaced. If that reads low, it will run more lean and that will cause higher in-cylinder temperatures.

What color were the tops of the pistons?

dmayer84
10-27-2011, 11:49 AM
http://i164.photobucket.com/albums/u9/dmayer84/91e704d2.jpg

#7 is all the way on the right.

dmayer84
12-13-2011, 11:28 AM
Well we went to put the heads back on this weekend, but first roated the engine and noticed that part of the piston is missing in cyl #7. Photo below.

Anyone have any advice on what kind of lift to use to remove the engine, or directions for removing the engine?

http://i164.photobucket.com/albums/u9/dmayer84/IMG_0018.jpg

JimN
12-13-2011, 11:46 AM
Well we went to put the heads back on this weekend, but first roated the engine and noticed that part of the piston is missing in cyl #7. Photo below.

Anyone have any advice on what kind of lift to use to remove the engine, or directions for removing the engine?

http://i164.photobucket.com/albums/u9/dmayer84/IMG_0018.jpg

That sucks.

If you have room in your garage (or if the weather cooperates when it's time to remove it), you may be able to maneuver an engine hoist (http://www.harborfreight.com/2-ton-foldable-shop-crane-35915.html) but it may be hard to raise the engine enough to clear the gunwales when you try to move the boat out of the way. Another way is to use a chain hoist (http://www.harborfreight.com/1-ton-chain-hoist-996.html), if you have or can build a beam to support it. If you build something, it will need to support at least 1000 lb (a little bit of margin built in). If you want to build something, look at this for ideas (http://www.harborfreight.com/1-ton-telescoping-gantry-crane-41188.html). It could be made of wood as long as it's braced to keep the vertical members from rotating at the base. I would use 4x4 for the vertical members, 2x6 for the horizontal (one on each side of the 4x4, through-bolted at the top with a piece of 4" blocking between them) and 2x6 at the base with strapping to keep it from rotating. A piece of chain with a D-link can be used to attach the chain hoist. The top would need to be at least 8' from the floor, 9'-10' would be better.

1redTA
12-13-2011, 11:52 AM
any cherry picker should work, if you have any body with a chain fall on an A frame use that. The pistons are really gummed up for a modern roller engine, a broken piston like that probably came from some pre ignition IMO. I would find what is causing that condition EGR? intake leak? seems the marine versions are missing what auto 's have.

The rebuild should be easy, locate a piston, slap it in R&R enjoy

CantRepeat
12-13-2011, 12:12 PM
any cherry picker should work, if you have any body with a chain fall on an A frame use that. The pistons are really gummed up for a modern roller engine, a broken piston like that probably came from some pre ignition IMO. I would find what is causing that condition EGR? intake leak? seems the marine versions are missing what auto 's have.

The rebuild should be easy, locate a piston, slap it in R&R enjoy

That's going to depend on how the cylinder walls look. :(

dmayer84
12-13-2011, 12:37 PM
From what we can see the cylinder walls appear to be in good condition. Trying to locate a gantry crane in the area to rent, dont think a regular hoist will work.

Might trailer it to my fathers friends garage who has a built in over head rail system.

Table Rocker
12-13-2011, 01:33 PM
Trying to locate a gantry crane in the area to rent, dont think a regular hoist will work.If you are close, you could take the wheels off the trailer and lower it down another 6-8" or so. If it just a couple of inches, let the air out of the trailer tires.

Reverend Bob
12-13-2011, 01:55 PM
It looks like it has automotive head gaskets???????

-V-
12-13-2011, 01:56 PM
It looks like it has automotive head gaskets???????

is there a difference?

dmayer84
12-13-2011, 01:59 PM
That was the head gasket that was there from the factory when we got the boat. We got a set of the fel pro marine gaskets that we are using going forward.

TOO-TALL
12-13-2011, 03:33 PM
That sucks I know just what your going threw.where is the ect valve located?I have the mxc is the ect on the mcx.I'm thinking I should replace mine

mikeg205
12-13-2011, 06:51 PM
http://i164.photobucket.com/albums/u9/dmayer84/91e704d2.jpg

#7 is all the way on the right.

what is that stuff on the inside area of cylinder #3 - looks like rust?... the pistons look really corroded.. is that normal? I have never seen that... lot's carbon... but not pitted like that.... I'm no expert - but when Too-Talls engine failed at 1008 - the pistons still looked like new accept for a little scoring from failure....:confused:

Jerseydave
12-13-2011, 07:26 PM
From what we can see the cylinder walls appear to be in good condition. Trying to locate a gantry crane in the area to rent, dont think a regular hoist will work.

Might trailer it to my fathers friends garage who has a built in over head rail system.

Overhead rail system would be the best. I used a front end loader several times to pull my big block out of my jet boat years ago only because I had one on the farm.
Sorry to see you have to go through this tear-down but at least it's the off season for us here in Jersey. If you need any help after the holidays I should be available.

dmayer84
12-13-2011, 08:01 PM
Looks like I got a hoist that is big enough to reach into the boat. My vacation between Xmas and new years that was for relaxation will now be when the engine is pulled and hopefully replaced. Trying to see if the engine shop would be able to do the turnaround .