2012 VP 300 C-A Exhaust manifolds getting too hot - DTC 441 & 442

Donald0039

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Not sure what to think. Things were changing soo fast during these years, support material couldn’t keep up. This is why techs are trained in how the systems work, so when we get conflicting info we can find were the answer is.

The diagnostic manual for the 2 serial numbers you have posted shows this engine as using 2 EGT sensors to monitor riser/elbow temp. They don’t even list the 441,442 codes.

The wiring diagram is the same for both S/Ns. It shows 4 temp sensors. None of them EGT sensors.

The parts breakdown is kind of iffy for this engine. It shows 2 temp sensors. It also shows that if you wanted a TPS you would have to buy the complete throttle body, sure hope that’s a typo/glitch. Also shows that if you want replacement heat exchanger cap gaskets ---- you have to buy a heat exchanger? That’s crazy because when you service the heat exchanger on this engine, you remove the end caps and clean it out. You only back flush / chemical flush sealed heat exchangers.

I’m not sure what your engine has. I can’t see your engine. The only question you’ve answered is what the FMI numbers are. At this point I’m not even sure if your manifolds are raw water cooled. Have you loosened any hoses to see what comes out? The only way anyone can help you is if you answer questions 100% correct. If you’re not sure, just ask and we can help you.

did you post a pic of the O2 feedback monitor? ERWT sensor temperature and voltage information is only available in Diacom’s O2 Feedback Monitor.
A lot depends on what you have. Do you have a Temperature Control Device (TCD) or a Pressure Control Device (PCD) and what one do you have?
Maybe post a pic of what you have? I would hate to give you advice on how to service a TCD if you have a PCD
Your engine may have 1 or 2 temp sensors on each manifold, they will look the same. Do you know how many you have? They will have 1 or 2 wires.
If you look at Diacom do you see temps for EMWT and ERWT?

Like I said a couple of times before.
The temperature control devices are the most common cause of this problem. They are also the easiest and cheapest to check.
Could the problem be somewhere else? Sure could, might even be electrical (you said earlier something about shooting the manifold temps—did you?) maybe do a clear hose test, maybe a total water output test, maybe inspect the heat exchanger and replace the rubber cap gaskets --- they tend to start to go bad at this age and expand so they block the water flow.
The boat is at a marina on a rack, so it's not like I can do testing every afternoon. The manifolds each look to have two identical looking sensors, one in the exhaust manifold towards the front of engine and one in exhaust elbow (riser) towards the rear.

I was thinking of pulling the endcaps off the heat exchanger but the gaskets are not listed in the parts diagram. How would I get new gaskets? Can one pull the guts of the heat exchanger out to soak or it's it basically one piece all soldered together except for the endcaps?

Could I be low on coolant in the overflow and that is the problem? I see what looks to be 1/2" of coolant in the bottom of the overflow. Trying to get some Volvo Penta VCS but no place seems to stock it and these are VP authorized dealers.

I see nothing in the Diacom about a ERWT. Only EMWT.

I plan on going to the boat Thur or Fri afternoon to work on it. Run it on muffs and get some temp readings with IR temp gun. Maybe run it with the water going into the flushing port bypassing the oil cooler.

Not sure about pulling the heat exchanger endcaps without replacement gaskets in hand.

Other suggestions of things to check or test?
 

muc

"Retired" Association of Marine Technicians...
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The boat is at a marina on a rack, so it's not like I can do testing every afternoon. The manifolds each look to have two identical looking sensors, one in the exhaust manifold towards the front of engine and one in exhaust elbow (riser) towards the rear.

I was thinking of pulling the endcaps off the heat exchanger but the gaskets are not listed in the parts diagram. How would I get new gaskets? Can one pull the guts of the heat exchanger out to soak or it's it basically one piece all soldered together except for the endcaps?

Could I be low on coolant in the overflow and that is the problem? I see what looks to be 1/2" of coolant in the bottom of the overflow. Trying to get some Volvo Penta VCS but no place seems to stock it and these are VP authorized dealers.

I see nothing in the Diacom about a ERWT. Only EMWT.

I plan on going to the boat Thur or Fri afternoon to work on it. Run it on muffs and get some temp readings with IR temp gun. Maybe run it with the water going into the flushing port bypassing the oil cooler.

Not sure about pulling the heat exchanger endcaps without replacement gaskets in hand.

Other suggestions of things to check or test?
!st thing you need to do is determine what cooling system you have on this engine. There are 4 different ones and what to do next depends on what you have.

Inspecting the heat exchanger on an engine this old is always a good idea. Yes I highly recommend you have new end cap gaskets before disassembly. They tend to swell up with age and can restrict raw water flow. The heat exchanger is usually one piece all soldered together except for the endcaps. You can’t inspect the anti-freeze side, only the raw water side. Cleaning of the tubes is usually done with a long handled brush like is used for cleaning a .22 caliber rifle barrel. EDIT: ask a Volvo penta dealer about getting new gaskets, if they can't get them from Volvo they will be able to find them aftermarket.

Yes low coolant could cause this problem, but only on some systems. You could try a Volvo truck dealer for VCS or in an emergency there are coolants that cross reference. Always keep the coolant level where it should be --- bad things happen if there is too much air in the system. Also you do change the coolant every 4-5 years? Yes it's important.

Have you looked at the O2 feedback monitor? If you have 4 sensors you WILL have 4 different readings. Because these 4 sensors are exactly the same, is it possible someone in the past got the electrical connecters mixed up? I’ve seen it happen.

I recommend all cooling system troubleshooting be done in the lake. If you aren’t familiar with how running on a hose is different from running in the lake, it can lead you to wrong conclusions.

If you have exhaust thermostats like I posted a picture of, remove one and disassemble it to check if the piston is free to move.

There are many different ways to troubleshoot this problem, but it depends on what cooling system you have. So loosen some hoses to see where you have water and where you have coolant. And picture always help.
 
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Donald0039

Petty Officer 3rd Class
Joined
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Messages
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!st thing you need to do is determine what cooling system you have on this engine. There are 4 different ones and what to do next depends on what you have.

Inspecting the heat exchanger on an engine this old is always a good idea. Yes I highly recommend you have new end cap gaskets before disassembly. They tend to swell up with age and can restrict raw water flow. The heat exchanger is usually one piece all soldered together except for the endcaps. You can’t inspect the anti-freeze side, only the raw water side. Cleaning of the tubes is usually done with a long handled brush like is used for cleaning a .22 caliber rifle barrel. EDIT: ask a Volvo penta dealer about getting new gaskets, if they can't get them from Volvo they will be able to find them aftermarket.

Yes low coolant could cause this problem, but only on some systems. You could try a Volvo truck dealer for VCS or in an emergency there are coolants that cross reference. Always keep the coolant level where it should be --- bad things happen if there is too much air in the system. Also you do change the coolant every 4-5 years? Yes it's important.

Have you looked at the O2 feedback monitor? If you have 4 sensors you WILL have 4 different readings. Because these 4 sensors are exactly the same, is it possible someone in the past got the electrical connecters mixed up? I’ve seen it happen.

I recommend all cooling system troubleshooting be done in the lake. If you aren’t familiar with how running on a hose is different from running in the lake, it can lead you to wrong conclusions.

If you have exhaust thermostats like I posted a picture of, remove one and disassemble it to check if the piston is free to move.

There are many different ways to troubleshoot this problem, but it depends on what cooling system you have. So loosen some hoses to see where you have water and where you have coolant. And picture always help.
Went to the boat this morning. The overflow had about 1/2" of coolant in the overflow. Started to add a gallon of coolant and it took the whole gallon and when finished adding the gallon the overflow was maybe 1". Still not where it needs to be. The The coolant was obviously flowing into the engine or manifolds. I am thinking low coolant may be the problem. Now to hunt down more VP VCS coolant since I got the last gallon from a mail-order company. I intend to fill it until it's at the proper level which is at the seam between the top and bottom sections of the overflow.

Some engine pictures:
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Lou C

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I see a fitting on the upper section of the manifold that shows a leak trail to the bottom section. If you can stop that leak it may help keeping the H/E full. Also to bleed the air out of the HE I like the Lisle radiator funnel. This works great at getting the air out without spilling AF all over the place.
Looking at those pix I’ll shedding a few tears over lost simplicity…lol….
 
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Donald0039

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Jun 11, 2022
Messages
78
I see a fitting on the upper section of the manifold that shows a leak trail to the bottom section. If you can stop that leak it may help keeping the H/E full. Also to bleed the air out of the HE I like the Lisle radiator funnel. This works great at getting the air out without spilling AF all over the place.
Looking at those pix I’ll shedding a few tears over lost simplicity…lol….
Thanks. Not really seeing it. What picture number?
 

Lou C

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1&2 fitting on upper section of manifold with a small hose connected. Tell tale stain on lower part of & Y pipe.
 

Lou C

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See it now?VP manifold.jpg

the lost simplicity I was referring to:
simple old style V/P exhaust system
This was a retrofit to an OMC 4.3 V6 that originally came with the OMC one piece manifolds that have long since been NLA. I knew that OMC changed to this later system before being bought out by V/P in '93/94 so I just got a Barr Marine aftermarket manifold & elbow set and used VP parts to mate it with the OMC Y pipe. Fit like factory and no leaks. Easy and cheap to replace when needed, here in the salt pond, by about 7 seasons. Like $725 for parts and 3 hrs my labor. To replace that EPA required abomination when needed will be close to $6000. I rest my case.
4.3 with new exhaust system.png
 

Donald0039

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Messages
78
See it now?View attachment 369913

the lost simplicity I was referring to:
simple old style V/P exhaust system
This was a retrofit to an OMC 4.3 V6 that originally came with the OMC one piece manifolds that have long since been NLA. I knew that OMC changed to this later system before being bought out by V/P in '93/94 so I just got a Barr Marine aftermarket manifold & elbow set and used VP parts to mate it with the OMC Y pipe. Fit like factory and no leaks. Easy and cheap to replace when needed, here in the salt pond, by about 7 seasons. Like $725 for parts and 3 hrs my labor. To replace that EPA required abomination when needed will be close to $6000. I rest my case.
View attachment 369914
Thanks for pointing it out.
 

Donald0039

Petty Officer 3rd Class
Joined
Jun 11, 2022
Messages
78
See it now?View attachment 369913

the lost simplicity I was referring to:
simple old style V/P exhaust system
This was a retrofit to an OMC 4.3 V6 that originally came with the OMC one piece manifolds that have long since been NLA. I knew that OMC changed to this later system before being bought out by V/P in '93/94 so I just got a Barr Marine aftermarket manifold & elbow set and used VP parts to mate it with the OMC Y pipe. Fit like factory and no leaks. Easy and cheap to replace when needed, here in the salt pond, by about 7 seasons. Like $725 for parts and 3 hrs my labor. To replace that EPA required abomination when needed will be close to $6000. I rest my case.
View attachment 369914
I had a Cruisers Inc 1987 24' boat with a Mercruiser 268?? (5.7L) engine and an Alpha One outdrive. With carb. Gave it to Boat Angel. I think they sold it for $87. (Yes less than $100).
Everything was simple. But still needed work.
 

Lou C

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Yes all boats will need work; I’ve done a lot on my old 1988 Four Winns 4.3/Cobra. However for old boats affordable parts are kind of a make or break thing.
 

Donald0039

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So looking at parts diagram for a VP V8 300 C-A. Ref # 54161974 is not for my engine.
Ref # 54161345 looks correct for my engine. Shows a thermostat on the heat exchanger (#2) that is part of the closed cooling system (coolant).
Ref # 54161973 is not for my engine.
Ref # 54161344 looks correct for my engine.

Looks like the sea water flows into the exhaust elbow from the bottom via fitting (#11) that has a blue plastic drain plug on the bottom
 
Last edited:

Donald0039

Petty Officer 3rd Class
Joined
Jun 11, 2022
Messages
78
See it now?View attachment 369913

the lost simplicity I was referring to:
simple old style V/P exhaust system
This was a retrofit to an OMC 4.3 V6 that originally came with the OMC one piece manifolds that have long since been NLA. I knew that OMC changed to this later system before being bought out by V/P in '93/94 so I just got a Barr Marine aftermarket manifold & elbow set and used VP parts to mate it with the OMC Y pipe. Fit like factory and no leaks. Easy and cheap to replace when needed, here in the salt pond, by about 7 seasons. Like $725 for parts and 3 hrs my labor. To replace that EPA required abomination when needed will be close to $6000. I rest my case.
View attachment 369914
What do you think is wrong with the leaking hose connection? Hose damaged? Clamp damaged. Past the threads? The question is will I be able to unscrew the fitting from the exhaust elbow or might it snap.
 

Lou C

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9,999
Hard to say but check if the fitting is loose or the clamp is loose. Might be necessary to just carefully tighten…
 

Donald0039

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Hard to say but check if the fitting is loose or the clamp is loose. Might be necessary to just carefully tighten…
In the parts diagram it looks like it seals with a O-ring meaning it's almost certainly not NPT. Maybe get a new O-ring and re-do the connection.
 

muc

"Retired" Association of Marine Technicians...
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Agree that Ref # 54161345 + Ref # 54161344 look to be correct for your engine.
You don't have a TCD or PCD. I've never worked on one of this style freshwater cooled engines. It looks close to the 6.0L, but that engine had a vertical heat exchanger.
Low anti-freeze sure would cause the issues you're having.
Volvo VCS is an organic additive technology (oat) based coolant and I've been told OAT doesn't like being exposed to air. If you haven't changed your coolant in the last few years, I would take this opportunity to do it now. A drain and flush would be a good idea.
That leak you see is lake water, Best do a pressure test to see why and where you're loosing coolant.

Coolant flow in the full closed cooling system is out of the circulation pump, into the engine block, through the heads, and into the lower intake manifold. Coolant then flows out of the intake manifold into a ‘T’ that feeds into the bottom of each exhaust manifold. Coolant then flows through the exhaust manifold and out where the manifold thermostats used to be located through a new fitting into another ‘T’ and then back to the engine thermostat housing at the entrance to the heat exchanger. There are no exhaust manifold thermostats. The thermostat housing contains a bypass from the intake manifold to the circulation pump. When the thermostat opens, the bypass is blocked off and all coolant flow is then directed into the heat exchanger and back to the circulation pump. Exhaust manifold temperature is controlled by the engine thermostat. A gasket prevents flow between the manifold and the elbow. When removing the elbow, it is necessary to drain the coolant in the manifold first.
 

Donald0039

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So had the boat put in the water today. Added another 1.5 gallons for a total of 2.5 gallons. (It's possible the jugs of VP VCS coolant are 5L rather than a gallon). Started engine, level went down a bit. Added a little more coolant. Did that twice. Third time the the coolant level did not drop, when the level started to rise I screwed on the cap for the overflow.

Let the engine run until it had a red triangle alarm. It seemed to take longer before the alarm than before. When the alarm sounded the engines the engine coolant temp was 145F the previous tests it's was only 86F. By IR temp gun the exhaust manifold was overheating but the exhaust elbow was fine at 125F.

The DTC was pretty much pretty much the same except the engine coolant was hotter at 145F.

Owners manual does not talk about burping air from cooling system. Just fill to full line on overflow, start engine keep adding coolant to keep at full line then screw on cap on the overflow container. Essentially what I did.

So I am thinking there is still air in the cooling system or a thermostat. Block not overheating and exhaust elbow not overheating (raw water cooled). Only exhaust manifold. Same temps roughly on both sides for exhaust manifolds and exhaust elbows (meaning both exhaust manifolds were overheating and both exhaust elbows were fine).
 

Lou C

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If you can try getting one of those Lisle radiator funnels they work well for that purpose. Seeing as how the manifolds are antifreeze cooled (correct?) and the design has that tall section there appears to be places for air to collect if there was a small leak.And, the top of the manifold is higher than the top of the H/E which is where you’d typically bleed the air from. Ideally you’d bleed air from the highest point in the cooling system but I’m not sure if Volvo allowed for that, however there may be a way to do it….
 

Donald0039

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Well the coolant is in now. Was filled to the full mark after a few minutes of running. Owners manual does not mention any need to bleed any air. But there certainly could still be air. Unsure
 

muc

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“The DTC was pretty much the same“
Do you mean like only one number off?
What did the four exhaust temp senders read?
 
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