Volvo Penta - Intake Manifold Crack

[dabbenante]

2001 Larson Boat with Volvo Penta 5.0 GLPEFS - Inboard/Outboard. Carburetor

Water was leaking within engine hull area. Brought to dealer and he said circulating pump was bad and replaced. Water was leaking following week and enging running rough at idle and limited power. Found that seawater pump had bad seal and replaced seawater pump. (Realize now that dealer probably replaced wrong pump). Took for a ride this past weekend and no water leaking but started hearing an intermittent chirping alarm (temp gauge was fine) and engine was running rough (suddenly not able to get above 2500 rpms) and oil pressure gauge was reading low oil pressure when at low rpms. Limped back in and brought back to dealer.

Dealer said he thought water line through transom was bad and needed to take out of the water to fix. Called today and said that he removed the thermostat housing and that there is a hole in the intake manifold right by the hot water sensor. The hole is actually on the screw casing of the heat sensor located on the intake manifold. It looks as if it was broken when someone put something like a screw driver in between the thermostat housing and the manifold to pop of the thermostat housing but I could be wrong.

So, I can purchase a new intake manifold for $800 plus the cost to install or I can take the boat back home, pull the manifold and have my brother-in-law that runs a machine shop try to do some welding magic. The dealer is not sure that the "hole" in the manifold was the cause of my problems but cannot test anything else until it is fixed. He says both the oil and hot water sensors are bad. I am thinking the thermostat was bad or clogged the whole time and kick myself for not doing it myself.

Any advice on how to handle the exhaust manifold repair or replacement.

Thanks

 

[dingdongs]

Re: Volvo Penta - Intake Manifold Crack

get yourself some jb weld off ebay.clean up area and spread on and test.if it fixes cracked cylinder blocks with 4" splits your problem is gonna be a breeze.

 

[dabbenante]

Re: Volvo Penta - Intake Manifold Crack

JB Weld sounds like a good starting point. Thanks for the advice.

 

[honeys money]

Re: Volvo Penta - Intake Manifold Crack

JB can work good, how clean you get the spot that your going to patch is a huge factor of how well and long it will work.

 

[dabbenante]

Re: Volvo Penta - Intake Manifold Crack - Follow Up

Re: Volvo Penta - Intake Manifold Crack - Follow Up

Had the shop take off the cracked manifold and my-brother-in-law had his machine shop weld it all back (cost me dinner and a few beers instead of $800 for a new manifold). It seems the corrosion had developed from the underside. The manifold was put back on by the volvo penta shop and they said some of the bolts holding down the manifold were not torqued (and somewhat loose) when they initially took off the manifold. The replaced all sensors and everything seemed fine last night when I took it out. However, as we were coming into the dock, after going at a slow idle for some time, the low oil pressure buzzer went off. The shop had tested the oil pressure with a guage and it had reflected adequate pressure. The oil sending unit and and the oil pressure sensor have been replaced so it must be the actual gauge on the dashboard or wiring. Of course it could be the oil pump but since I would then have take out a new mortgage to fix that problem, I am going to get my own direct gauge or try to run a new direct wire.

Thanks for the feedback and I am open to comments on the lingering oil pressure.

 

[Don S]

Re: Volvo Penta - Intake Manifold Crack - Follow Up

Re: Volvo Penta - Intake Manifold Crack - Follow Up

after going at a slow idle for some time, the low oil pressure buzzer went off.

How do you know it was the oil pressure alarm and not over temp? It's the same buzzer.

Also, the gauge sender and the alarm switches are NOT the same unit.

 

[dabbenante]

Re: Volvo Penta - Intake Manifold Crack

The dashboard oil gauge dropped to the red-line and the oil icon lit up on the dashboard as well. When I increased the RPM's the oil pressure lifted on the dash board guage and the oil icon went out. So if the oil sending unit has been replaced, the oil pressure sensor has been replaced and when the shop connected the direct gauge to my sending unit and said the pressure was fine, I am thinking that was because it was in a non-typical situation and thought that by buying a gauge and monitoring out on the water, I might get a different reading or at least determine if it is my dashboard gauge.

I hope you are not saying that if the alarm is going off and the dashboard gauge is showing below the red-line that I have independent alarms telling me the same thing (that I have a problem).

Eager to hear your thoughts.

 

[GLENN M]

Re: Volvo Penta - Intake Manifold Crack

that is exactly what he is telling you.

 

[dabbenante]

Re: Volvo Penta - Intake Manifold Crack

After extensive research it seems that Volvo stopped making a 30 SAE non-synthetic oil. Some online groups specifically warn against using the new Volvo 30 SAE synthetic oil in older engines as in some cases the engines run hot. I pulled out my service tickets from last year (had it serviced right after purchasing the boat) and confirmed that the shop put in the Volvo synthetic oil. Looked at previous owner's records and he was not using the synthetic oil.

It seems like the oil must be the common denominator as everything else has been checked and this seems to only be an issue afer the engine has been running fast (heating up the oil) and then drops when we idle in through a three mile canal to the dock. Am I making any sense? It seems like the dealership is scratching their head on this one and everything that can be readily replaced or repaired has been done. Also, the engine has relatively low hours on it (130 hrs and only 85 when I bought it) and it is a 2001 boat but do not know if that matters or not.

So should I do any or all of the following:
1. change the oil to a non-synthetic oil
2. buy a gauge with a tach and run it
3. put in earplugs and cross my fingers

 

[dabbenante]

Re: Volvo Penta - Intake Manifold Crack

I replaced synthetic oil with regular 30 weight and pressure issues have improved. However, also discovered that the mechanic that replaced the intake manifold did not tighten the distributor cap so the timing was also off. Adjusted the timing, tightened the distributor cap, and replaced the oil synthetic oil. Boat is running great today.

Thanks for the feedback folks.

 

[cc190cc]

Re: Volvo Penta - Intake Manifold Crack

I would not JB weld, if that hole got there from corrosion/rust I would imagine the rest of the intake is in just as bad of shape. If a hole pops through in the right place you will fill the motor with water and destroy it. 800 for an intake, try checking online, you can find one cheaper than that.

Find somethign cast iron. It doesnt necessarily have to be "marine". Stay away from aluminum and make sure you get the right intake (bolt holes differ). I would say if you are willing to JB weld it you should be willing to put a non marine intake on it for a couple hundred bucks. There should be a part number on top of the intake, it will be stamped/cast. If you search that number or post it on here someone will help you find one.

Chad

 

[cc190cc]

Re: Volvo Penta - Intake Manifold Crack

disregard, should have read past JB weld, im glad you didnt do that, i would still imagine the internal water jackets on the intake are in bad shape.