Blocked E-TEC...

BogMonster · 12 November 2011, 12:12

I posted this on the Etec owners forum yesterday but as yet no responses so thought I would try here as well:

I had a fight with some thick kelp last time I launched a couple of weeks ago and when powering up onto the plane once I had launched, I almost immediately got an overheat alarm. Flipped the i-Command to the temperature reading and it was 90 something, a blast astern produced a lot of minced kelp (there was obviously a load wrapped round the leg) and then it cooled down again.

However I have been out again today and it is not running as cool as it did - it tends to sit at around 70 degrees Centigrade where it used to quickly drop back to about 40-50 or so. Sometimes it gets down to 55 or so but sometimes it doesn't.

So it isn't actually overheating but neither is it quite right and the tell-tale, while it's pumping, isn't as strong as it should be so I reckon there is still some muck stuck inside somewhere.

I took the plastic side intake screens off the leg and blasted some water in there with a hose and some small bits of kelp came out the holes in the front of the leg but I wondered if there are any other restrictive places in the cooling system that might be likely to be blocked up with small bits of kelp?

In particular - where is the thermostat on the 150 and how do you get to it? I wondered if it is worth taking that out and flushing it through. Having searched I also see a reference to a "poppet valve" - where is this / could it get blocked with weed? I have looked on the parts section of BB's website and I can't even find the thermostat listed anywhere - I can see the poppet valve but it isn't obvious where on the engine it is located.

Erin · 12 November 2011, 13:18

I think poppet valves are normally located about halfway down the leg. If the water supply was blocked and the telltale isn't as strong as it used to be, perhaps the impellor has worn a bit. Worth taking a look.

Tony Barber · 12 November 2011, 14:06

Hi.

Do the gauges tell you if it was an engine or engine management overheat? I think you may need the diagnostic software to tell the difference?

I'm not familiar with the 150, but on a 200 HO it's worth clearing out the fuel vapour separator as if that gets blocked it restricts the flow of water through the EMM and can trigger an overheat alarm.

Tony

Pikey Dave · 12 November 2011, 15:06

Steve, the 'stats are mounted in the heads at the rear of the block as viewed from inside the boat. If you stand outside the boat looking towards the engine you will see 2 large plastic caps with hex heads about midway up the heads, one on each side. Off the top of my head I think they are around 24mm af. They should unscrew pretty easily. If you cant find 'em I'll scan the page from the manual & send it to you.

PS The idling temp should be around 65-70 deg C so your're not far off. What is the temp like at full chat?

gotchiguy · 12 November 2011, 16:29

We've had a number of overheat warnings over the years and despite having the mechanics look at it multiple times there does not appear to be anything wrong. It is usually at a specific RPM that if it is left there long enough the temperature just keeps rising. The alarm goes off at 100C and the engine will shut itself off at 120. Apparently damage is unlikely to occur until 125+. As soon as the alarm goes off a burst of acceleration or bringing it down to idle will see the temperature plummet down. Obviously it still happens when you least expect it however now that the navigator has the temp readout on the Raymarine it should happen far less often.

BogMonster · 12 November 2011, 17:13

Quote:

Originally Posted by Pikey Dave

Steve, the 'stats are mounted in the heads at the rear of the block as viewed from inside the boat. If you stand outside the boat looking towards the engine you will see 2 large plastic caps with hex heads about midway up the heads, one on each side. Off the top of my head I think they are around 24mm af. They should unscrew pretty easily. If you cant find 'em I'll scan the page from the manual & send it to you.

PS The idling temp should be around 65-70 deg C so your're not far off. What is the temp like at full chat?

Thanks, will have a look.

I plugged the computer in this morning and downloaded the EMM data - both the engine and the EMM look to have been getting a little warm as it had logged the faults below:

25 2 47:14 47:15 -- EMM temperature above expected range
RPM=0; TPS=0%; Baro=100Hg; Air=33°C; Port=103°C; Stbd=106°C; EMM=92°C; Exh=0kPa; WP=0psi; SV=52V; BV=14V

70 1 47:14 47:15 -- Engine temperature above expected range low speed - Starboard
RPM=648; TPS=0%; Baro=100Hg; Air=33°C; Port=108°C; Stbd=111°C; EMM=98°C; Exh=17kPa; WP=0psi; SV=56V; BV=14V

40 1 47:15 47:15 -- Engine temperature above expected range low speed - Port or single
RPM=550; TPS=5%; Baro=100Hg; Air=34°C; Port=110°C; Stbd=113°C; EMM=98°C; Exh=13kPa; WP=0psi; SV=56V; BV=14V

Given that the initial overheat warning was definitely associated with kelp round the leg, and I found some bits of it jammed into the leading edge intake holes, I am pretty sure that what happened is that it was wrapped around the leading edge of the leg and as the speed came up, some of it was squished in through those holes by the drag from the water pulling on the long kelp strands.

What I have noticed (because I watched the temp profiles when it was performing normally so that I knew what to expect) is that it's running warmer than it was. Before, when you opened the throttle to anything over 3000rpm the temp would drop off pretty quickly to 40 something and now it drops back much slower and sometimes doesn't come down much and stays at 60-70 but the odd thing is that it isn't at all consistent - I was fiddling yesterday and throttling up to say 4000rpm till the temp stabilised, dropping back to idle for a minute or so, then doing it again and it wouldn't do the same thing each time, sometimes the temp would drop back a lot and sometimes just a bit, very strange. So I think maybe there is some crap whistling around in a cooling gallery and occasionally blocking off some of the flow. I need another sea trial to see if the stuff I flushed out yesterday has solved the problem but just wondering where else it might stick in the system.

Chris · 12 November 2011, 18:35

Quote:

Originally Posted by BogMonster

I posted this on the Etec owners forum yesterday but as yet no responses so thought I would try here as well:

I had a fight with some thick kelp last time I launched a couple of weeks ago and when powering up onto the plane once I had launched, I almost immediately got an overheat alarm. Flipped the i-Command to the temperature reading and it was 90 something, a blast astern produced a lot of minced kelp (there was obviously a load wrapped round the leg) and then it cooled down again.

However I have been out again today and it is not running as cool as it did - it tends to sit at around 70 degrees Centigrade where it used to quickly drop back to about 40-50 or so. Sometimes it gets down to 55 or so but sometimes it doesn't.

So it isn't actually overheating but neither is it quite right and the tell-tale, while it's pumping, isn't as strong as it should be so I reckon there is still some muck stuck inside somewhere.

I took the plastic side intake screens off the leg and blasted some water in there with a hose and some small bits of kelp came out the holes in the front of the leg but I wondered if there are any other restrictive places in the cooling system that might be likely to be blocked up with small bits of kelp?

In particular - where is the thermostat on the 150 and how do you get to it? I wondered if it is worth taking that out and flushing it through. Having searched I also see a reference to a "poppet valve" - where is this / could it get blocked with weed? I have looked on the parts section of BB's website and I can't even find the thermostat listed anywhere - I can see the poppet valve but it isn't obvious where on the engine it is located.

Difficult one to know where to start. If the kelp has gone though the impeller you would expect it be pulped and hopefully it would have all cleared.

What did the yanks suggest ?

Pikey Dave · 12 November 2011, 18:46

40 sounds a bit cool, they should run around 68 ish

willk · 12 November 2011, 19:24

98C for the EMM (which is water cooled) sounds dangerously high to me. That's basically boiling the cooling water. The water flow to it must be blocked.

captnjack · 12 November 2011, 19:41

Quote:

Originally Posted by Chris

Difficult one to know where to start. If the kelp has gone though the impeller you would expect it be pulped and hopefully it would have all cleared.

What did the yanks suggest ?

Its doesn't get as ground up as you think. I would pull the thermostats, they probably have bits of vegetation in them reducing flow. It gets hooked on the center loop and in the springs. I don't know where to find them on the Etec, although in general they are on the top aft portions of the powerhead.

Pikey Dave · 12 November 2011, 20:07

Steve, the emm is cooled by water from the block just before it goes out through the tell tale. You mentioned that the tell tale isn't as strong as normal. There might be a bit of crud in the small bore hose that goes to the emm.

BogMonster · 12 November 2011, 20:45

No replies over on the owners forum

I would have thought anything that was small enough to get in through the intake holes would not lodge in too many places - I guess they are only 4-5mm holes.

The overtemp was only very brief when the initial alarm went off - I guess maybe it lasted for all of 30 seconds. No problems with engine running and there have been no more alarms - just that I have been watching the temp gauge closely and noted it was running a bit warmer than usual but I guess you would say it is within an acceptable operating range.

The highest it has been in normal cruising has been about 80 C and the temp seems to drop back as you get nearer WOT.

Oh well I might pull the stats out and have a look - hopefully you don't need a new gasket or anything to put them back in...? I guess if they are plastic bungs they are probably sealed with an O ring? If it looks like new parts will be required I'll just go for another sea trial now I have removed at least some crap from the system and see if it is OK now.

Thanks all

Pikey Dave · 12 November 2011, 22:34

Yup they are "O" rings, put some grease on the threads when you put em back in. Might be worth taking the stats out & putting the hose on the flushing adapter by the tell tale & giving it a flush through.

Hightower · 13 November 2011, 02:06

I haven't experience on Etec's, but a back flush on the EMM pipework is probably easy to do and worth a go whilst you're looking at the thermostats.

Erin · 13 November 2011, 10:13

Those rpm's looked a bit low on your data download.

Pikey Dave · 13 November 2011, 16:18

Quote:

Originally Posted by Chris

What did the yanks suggest ?

JimH is still composing his reply, give him chance it's only been a couple of days

BogMonster · 13 November 2011, 20:04

Well I took out the thermostats and there was one tiny bit of green weed in the port bank and nothing in the starboard bank. Went out for a run and I think the temps are pretty much back to normal - definitely running cooler. The tell-tale (which I believe comes from the EMM) is hand-hot at idle (I'd guess about 40-45 degrees C) and warm at 2000rpm in neutral (again a guess - but 25-30 C) so I think that should be happy too. Going to plug in the computer and re-check the amount of time in each temperature band just to make sure but I think the problem is sorted.

Thanks for the input as always