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VP 57 wonbt start

T

tvanderv

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"My Volvo Penta 5.7 I/o about

"My Volvo Penta 5.7 I/o about 2 years ago would not start. Boat was on the trailer with stern drive in salt water. When the engine would not fire, I turned the key back to "on" and the motor ran backwards ( my dad referred to this in his generation as "dieseling - I know this was not due to a hot spot) and the engine cylinders filled with salt water. It hydrolocked but I did not know this, the starter motor burned up while trying to start the engine, and 1 week later the new starter motor would not turn over the engine. The salt water sat in the engine for a week and destroyed the motor. I was 1 month out of the 2 year repalce everything, no questions asked.waranty. $6000 later I got the boat back thanks to some help from Volvo and a new long block. Now fast forward to today. Again the motor would not fire, except when the key was turned from start to on. Then it "dieseled" again, spinning in reverse and belching vapors from the air intake/spark arrester. Fortunately I found a very knowledgeable mechanic who immediately diagnosed the problem as an ignition switch that had "bridged" due to moisture - what ever that means - and was only sending a spark at the moment of turning the key from start to on. This is exactly the same behavior I experienced before. This time there was no salt water, no hydrolock as when the serious dieseling happened I did not have the garden hose on with the Mickey Mouse flusing ears.

I have two questions:

1) why would the local mechanics and the Volvo Penta VP of Technical support not be able to diagnose the ignition switch isssue - is this so rare? and 2) no one has been able to explain why when the motor ran backwards for a short time it filled with salt water.
the new mechanic keeps ignition switches in stock and tells me he replaces them all the time.

Hope others can benfit from one expert and someone can solve the mystery of the hydrolock. I'm sure Volvo Penta tech services could benefit from what seemed to be impossible. Thanks"
 
"Tim, first, you are assuming

"Tim, first, you are assuming that the ignition switch theory was diagnosed correctly! This does sound very rare and absurd to me. We/you are at the mercy of their diagnostics, however.


**Here is a quote from an Internet source on the topic of Dieseling. This is very much as I would describe this:
<font color=""0000ff"">Dieseling occurs whenever fuel is ignited by another heat source other than a spark plug. (this means "spark source" ignition)

It could last a few seconds or few minutes, depending on the amount of fuel remaining in the combustion chamber and how long it takes for the ignition source to cool down.</font>

Dieseling, as I understand it, does not necessarily mean running in reverse direction, although an engine may run reverse for a portion of it! If running in reverse direction, the fuel/air source is depleted rather quickly and becomes non-existent.

Unless cylinder temperatures we extremely high and offered an ignition source, at the time that this occurred, I would almost foo foo the idea of dieseling under the guise of what we consider "dieseling".
Again, ignition source and fuel/air must be present for dieseling to occur.

Possible Causes:
Lean fuel/air ratio at low speed RPM.
High cylinder temperatures at low RPM..... carbon build up for example.
Both must be present!

Under normal conditions, with a normal weight flywheel, a properly working ignition system should never offer a spark "lead" (relative to piston position) that would cause reverse operation..... Ignition switch problem or NO ignition switch problem. (see ** above)

You mention that this occurs when the Key Switch position changes from Start to ON.
May we assume that this means when "Releasing the Key from Start position" back to "run" position?

You also do not mention the year model nor the ignition system. If this is late model, and uses an ignition module (ECU or ECM), you may have an issue with this module!
Did anyone suggest this?
Did anyone test this?
Did anyone change this?

I am not foo-fooing the idea of water reversion..... it sounds like this did indeed occur. You must find out why it occured since the mechanic apparently did not!
<font color=""ff0000""><font size=""+1"">Unless you have another $6k laying around, not being used
uhoh.gif
, I'd avoid using this boat until you have this issue completely resolved!</font></font>

I am eager to hear what others have to say about this.
"
 
"Ricardo, Thanks for the repl

"Ricardo, Thanks for the reply. I can only report what happened 2 years ago. It was not dieseling as you describe, as the engine was cold. It would not start with the outdrive in the water and the boat on the trailer. releasing the key from start to the "on" or run position resulted in the engine spinning backwards for a brief period. Coincidently, the engine cylinders filled with salt water, resulting in a hydrolocked condition. Attempting to start the engine with the water in the cylinders wiped out the starter motor. The boat dealer was brilliant - they told me I had a blown headgasket despite the clue that water came from both cylinder banks. They took off the heads, found only a lot of rust, had the heads rebuilt, emory cloth poilished as much of the cylinders as they could reach with the pistons in place, and reassembled the engine. The rust had done its damaage and the engine computer registered issues, so the long block ultimately was replaced. Foe a year the engine ( a 2005) ran fine, started every time, but this past time it would not start. It did, however, momentarily "fire" when the kepp was turned from start to run. Not every time, but maybe 25% of the start attempts. All but one time when this happened the alternator belt moved in the same direction as the starter motor turned the belt. But one time, just like 2 years ago, the engine started spinning backwards and shot a big puff of vapor out of the top of the engine. The key was in the run position, and not the off position. Again, there was no heat source for the traditional dieseling as you defined it.
So the boat is now with the mechanic and I will get it back in a couple of days. Hopefully he will be correct in his diagnosis. It is very clear that 1) the boat never fired once when the key was in the start position and 2) only when the key was released back to the run position did it occasionally fire. As the mechanic explained it, there was fuel in the cylinders and a spark avaialbel when the key went to "run", so that was what caused the engine to fire. Makes sense to me, but i am not a mechanic. We still have no explaination for the hydrolock and some have told me that an engine spinning in reverse can somehow cause water to enter the cylinders. All 8 were complete rusted, so there must ahve been a significant amount of water. The Volvo Technical expert mentioned a problem with the rizers, and another mechanic mentioned a poor design which removed a baffel, but I am not technical enough to understand these potential causes. The State Farm insurance company had an expert review the engine and the ircumstances and his conclusion was it was not an insurable event as the boat was not swamped. He suspected a design issue that he felt at some point would be exposed and possibly result in a recal, but I don't think that has happened. The boat dealer ( now out of business) told me he had replaced 2 other VP engines from similar hydrolock condition, but I recall both were within the 2 year warranty and they never tore them down or had a definitive diagnosis.

Hope that answers your questions Thanks for the interest."
 
"You need to consult with anot

"You need to consult with another technician and/or mechanic on this, IMO.

It is very simple to examine the phase of the ignition switch to see what/where the continuity is during either position...... Run and Start.
Both positions should power the ignition!

I assume that this engine is FI?

."
 
"It is fuel injected. Any idea

"It is fuel injected. Any idea how the previous engine filled with salt water? The hydrolock happened at the same time as the engine would not start. It turned over fine, then spun backwards. Someone must know how this could have happened as it was a catastrophic event to the engine and starter motor."
 
"If it did indeed turn over in

"If it did indeed turn over in reverse direction......, (even one or two revolutions), water reversion could have occurred, of which would explain the water in some cylinders.
(You mentioned earlier in your third sentence of your original post, that it "ran backwards")
That is when I explained about dieseling.

Yes, when a four cycle engine turns over in reverse direction, the exhaust system now becomes the "Intake" source!
Your exhaust has a direct connection to the level of the river/lake/sea water.

Cold water hitting hot pistons/valves causes problems."
 
Four cycle spinning backwards

Four cycle spinning backwards will ingest water if the exhaust system's outlet is submerged.

Thing that baffles me is what caused a cold engine to spin in reverse for what I can only guess was many revolutions?!?!??
 
"the outdrive was in the water

"the outdrive was in the water with the boat still on the trailer. It all happened fast and I could not stop the back spining and i guess thr water injection was what stopped it?? Volvo Tech Services said the engine could not run backwards, but clearly it did for a short time. The mechanic repalced the ignition switch just now and the boat started right up."
 
"ricardo, That would make ses

"ricardo, That would make sesne and since the boat was on the trailer on a steep ramp I suspect the level of the water in the exhaust system was not far from the level necessary to get sucked back into the engine. Perhaps if it had been floating freely and spun backwards the amount of water in the exhaust would have been less. I now get the connection between the back spinning and the watwer ingress. Thanks for clarifying how this could happen. It is very clear now the exhaust becoems the intake."
 
"I'm with Mark on this one

"I'm with Mark on this one! I can't for the life of me understand why it would run backwards and when not exceptionally HOT.... and not just spin one or two revs only..... but to run, as you suggest!
However, like said, one or two revs may be enough to ingest water.

Yes, being in the water and on the trailer if the hull attitude was just right, and the water being higher than normal...., may have added to this.
Hard to say from the cyber distance and key board here!

I'm going to still suggest checking out the ignition module. This must place the spark lead in the correct BASE mode when at low RPM. And it must do this consistantly!

The Key Switch thing sounds like a long shot, but as noted earlier....., it's easy to determine if you have an "open" ignition circuit when in "start position".

Do you still have the old ignition key switch?"
 
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