8.2 hot exhaust
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02-22-2015, 11:50 PM
#13
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Location: San Dimas Calif
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http://www.riverdavesplace.com/forum...-mag-PCM/page7
Best I can do . Need to figure out how to post a pic
Best I can do . Need to figure out how to post a pic
02-23-2015, 01:07 AM
#14
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iTrader: (9)
I see nothing posted about having your engine scanned here as I posted about that and gave some good info top of. Not to beat you up or anyone at river daves but your boat needs to be look at by a certified up to date Mercruiser shop USING scan testing equipment Merc CDS- G3. Very unlikely that someone on the net is going to pinpoint your problem but might as a truly lucky guess.
IMO you have a water flow problem of some sort, either a water flow problem / water restriction and or water volume problem as being not a enough - could even be a t-stat problem but who knows at this point especially without having eyes, hands, ears and a properly scanned engine including live data.
I really do not care your impeller has 22 hours as still being new and the housing, It takes only 30 seconds to hurt or completely damage either or both. Most likely you have dual water pickups in your outdrive correct ? do you have anything impeding water flow to your outdrive inlet water pickups ? do you have anything mounted on the transom and or under the boat hull that can be aerating the water flow or impeding water flow ? Have you ever started your engine on a water hose but forgot to plug up your water inlet pickups on the bottom of the outdrive ?
next - get your motor scanned and have it done with Merc CDS - G3 and see if the scan shows this fault text - PORTEMCT Overtemp. - this will mean that the port exhaust manifold is too hot. So it needs to be verified that the manifold temp is near the temp sensor. Check for parts condition of the water pump, housing, gaskets- O-ring(s) , any water leaks, clogged water hoses and or clogged exhaust or clogged coolers or clogged sea strainer.
next the certified Merc dealer can do a water volume test to see if that is the correct amount of water flow passing. This is a very easy test and I highly recommend it and the scan. With any of this your are throwing darts.
Next see if this fault text shows PO2S LeanRange PORT which will mean Port side post catalyst 02 sensor C stuck reporting lean.
or fault text- CATM OSC Index Port in which means port catalyst failed test and may be defective.
IMO you have a water flow problem of some sort, either a water flow problem / water restriction and or water volume problem as being not a enough - could even be a t-stat problem but who knows at this point especially without having eyes, hands, ears and a properly scanned engine including live data.
I really do not care your impeller has 22 hours as still being new and the housing, It takes only 30 seconds to hurt or completely damage either or both. Most likely you have dual water pickups in your outdrive correct ? do you have anything impeding water flow to your outdrive inlet water pickups ? do you have anything mounted on the transom and or under the boat hull that can be aerating the water flow or impeding water flow ? Have you ever started your engine on a water hose but forgot to plug up your water inlet pickups on the bottom of the outdrive ?
next - get your motor scanned and have it done with Merc CDS - G3 and see if the scan shows this fault text - PORTEMCT Overtemp. - this will mean that the port exhaust manifold is too hot. So it needs to be verified that the manifold temp is near the temp sensor. Check for parts condition of the water pump, housing, gaskets- O-ring(s) , any water leaks, clogged water hoses and or clogged exhaust or clogged coolers or clogged sea strainer.
next the certified Merc dealer can do a water volume test to see if that is the correct amount of water flow passing. This is a very easy test and I highly recommend it and the scan. With any of this your are throwing darts.
Next see if this fault text shows PO2S LeanRange PORT which will mean Port side post catalyst 02 sensor C stuck reporting lean.
or fault text- CATM OSC Index Port in which means port catalyst failed test and may be defective.
Last edited by BUP; 02-23-2015 at 01:35 AM.
02-23-2015, 09:46 PM
#16
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I believe Mercury changed the number of cats in the exhaust manifolds on the current model. I believe the first couple of years of production, the motors had 3 cats per manifold. I know that sounds odd, but I believe that's correct. That was changed to the current design which I think has one cat per manifold. I have a couple of the first 8.2's released with over 200 hours on them and have no paint peeling, dis-colored silent choice or tips. I don't feel the engine compartment gets any hotter than any of the previous Mercury power I've owned.
02-23-2015, 10:47 PM
#17
Banned
iTrader: (9)
the 3 cats in each exhaust total of 6 per engine was not a good idea from mercruiser as when one fails then all 3 could fail per side, kind of like a domino effect. This was a HUGE expense for the end user if any problems with the cats occurred and a huge expense for Merc with any dealer repair warranties that they (merc) had to cover. Better to pay for 2 than 6 cats plus a little less labor for the change out.
Indmar and Volvo and the rest of the smaller engine players had one cat perside including merc on their smaller engine packages.
The retail price for the cat design using 6 cats per engine was 1200 bucks for 1 cat only then times that by 6 - that's 7200 bucks just in cats not counting anything else if you had to buy all 6 / 3 per side.
How bad would the press be if you had to buy all 6 being the end user especially when other OEM engine builders had a totally of 2 cats per engine. This was one of the reasons among a few others for Merc changing to one cat per side plus their small block and V-6 already used 2 cats per engine from day one.
It did NOT make sense especially from the eyes of the end user, Merc dealers who really had to listen to that end user AND WARRANTY WORK costing Merc themselves from their over design expensive cat set up. Keep in mind the 8,2 Cat engine had some problems right out of the gate.
Volvo Penta has the least problems with the cats and 02 sensors - it is not even listed on their (Volvo) warranty radar. FYI
Indmar and Volvo and the rest of the smaller engine players had one cat perside including merc on their smaller engine packages.
The retail price for the cat design using 6 cats per engine was 1200 bucks for 1 cat only then times that by 6 - that's 7200 bucks just in cats not counting anything else if you had to buy all 6 / 3 per side.
How bad would the press be if you had to buy all 6 being the end user especially when other OEM engine builders had a totally of 2 cats per engine. This was one of the reasons among a few others for Merc changing to one cat per side plus their small block and V-6 already used 2 cats per engine from day one.
It did NOT make sense especially from the eyes of the end user, Merc dealers who really had to listen to that end user AND WARRANTY WORK costing Merc themselves from their over design expensive cat set up. Keep in mind the 8,2 Cat engine had some problems right out of the gate.
Volvo Penta has the least problems with the cats and 02 sensors - it is not even listed on their (Volvo) warranty radar. FYI
Last edited by BUP; 02-23-2015 at 11:56 PM.
02-24-2015, 10:49 AM
#20
Registered
The auto industry went through many learning curves when cats were put on cars / trucks , I wouldn't want to own a boat right now with
cats and be the guinea pig . A boat engine is under different load conditions then a car , I'm sure the engineers factored this in , but real world is different than the dyno ...
cats and be the guinea pig . A boat engine is under different load conditions then a car , I'm sure the engineers factored this in , but real world is different than the dyno ...
