cracked intake manifold on Volvo Penta 5.0FL

[BlueStreak]

Awesome forum here. I've been reading quite a bit since I discovered my unwinterized engine had 2 popped core plugs and a cracked intake manifold. I'm the original owner of this 1994 VP 5.0FL PDMA (Ford 302 V8) with the SX-S 1.66 drive. 466 hours in fresh water only.

The engine started normally--for the first post-winter startup--and I ran it for 2-3 mins before I noticed the rear plug on each side of the engine was out. Not knowing better, I put the core plugs back in and restarted, only to discover a crack in the intake manifold where it connects to the thermostat housing. The engine ran normally for the 20-30 seconds before I shut her down. (Upon pressurization, a finger-sized stream of water shot out of the crack in the intake manifold.)

I removed the intake manifold and can't find any cracks in the block valley nor on the engine block or head exteriors. No apparent water in the cylinder air intake ports. The one spark plug I pulled looked normal, no water. The engine oil looks clean and clear, not milky.

Initially, I figured I'd get another intake manifold and restart the engine. After reading some threads today, I'm thinking I need to at least pressure test (if not replace) the exhaust manifolds and risers before restarting the engine. In addition, I plan to do a cylinder compression check.

What's the likelihood that the block (or heads) cracked between cylinders or some other place not visible? Since the water is circulated thru the engine block then the heads before it gets to the intake manifold, I'm thinking any cracks there would have shown themselves? (Wishful thinking?)

Are there other things I should check before restarting the engine?

Thanks in advance for your comments and suggestions.

 

[rndn]

Re: cracked intake manifold on Volvo Penta 5.0FL

Welcome to the forum!!
If the block is not cracked, go play the lottery. It is very possible you only trashed the intake, although do the compression test to make sure. With that many hours, it is possible the exhausts are still okay, but to feel secure I would replace them if it were my boat. Make sure all else is okay prior to buying parts. You wouldn't want to buy the parts and then find out your block is cracked.

 

[njlarry]

Re: cracked intake manifold on Volvo Penta 5.0FL

With 500 hrs in fresh water, I'd inspect the exhaust manifolds and risers before replacing them. My '95 5.0 FL VP mainfolds and risers were inspected last season and still were fine.

 

[BlueStreak]

Re: cracked intake manifold on Volvo Penta 5.0FL

Thanks for the comments. I thought the storage space wouldn't freeze and got caught.

Do exhaust manifolds and risers typically survive freezing? Quite a bit of water (1-2 quarts each side) came out of them when I removed their hoses prior to removing the intake manifold. Or do I need to be concerned about internal cracks in them?

 

[dpgreen15]

Re: cracked intake manifold on Volvo Penta 5.0FL

what was the outcome of this? I purchased a used boat with a similiar problem. the front starboard freezeplug was popped and the front one on the port side was coming out. My intake was cracked slightly at the inlet housing. I am leaking no water after the aforementioned were fixed, and my oil is spotless. I am hoping to make out as well

 

[BlueStreak]

Re: cracked intake manifold on Volvo Penta 5.0FL

Wow...time flies...the outcome was I only had to replace the cracked intake manifold. I found a used one and it works fine. In fact, the reason I'm back here is the old (cracked) manifold is still sitting in my garage and I thought I'd post if someone is interested in it. I know it was difficult finding the right used one. The pic below shows the crack.

Also, the exhaust manifolds and risers were fine. The boat has run fine since the repair, but its been cold and rainy this Spring and hasn't been out yet.