Hi all, I have an askeladden beetle with mercruiser 1.7dti that suddenly started overheating..

[Theguy]

I was driving at 22knots and 3500rpm, just me in the boat. I went about 15km with no problems and a temperature of 90⁰, then I stopped to buy diesel, jumped in and started toward home, but then the alarm went off showing the temperature was too high, even though i was still only at 22 knots.. I waited a few mins for it to cool, them went on my way again, and got back up to speed without the temperature alarm going off again. All appeared normal again.  

Stopped for an hour and went out again, and now the temperature rises quickly again, meaning i can only go at 22 for a minute or so before it starts getting really hot.  

  

  

any idea as to why it would behave like that?

 

The engine is a mercruiser 1.7dti by the way.

[Swingswong]

Have you checked the impeller?

Maybe part of it has fallen off and blocking for water flow. 

[Theguy]

Aah, thats an idea!  Thanks, will check it out!!

[Bitteliten]

Well known on these engines that the heat exchanger cloggs over time. 
 

Treated either mechanicslly by open up and cleaned manually. Or chemically by acid  treatment (Systemrens)
 

check also that the waste gate actuator on the turbo moves as it shall. Can kill the engine if that is stuck. 
 

i think impeller is in the stern drive on these

Redigert 10.April.2023 av Bitteliten (see edit history)

[Theguy]

2 hours ago, Bitteliten said:

Well known on these engines that the heat exchanger cloggs over time. 
 

Treated either mechanicslly by open up and cleaned manually. Or chemically by acid  treatment (Systemrens)
 

check also that the waste gate actuator on the turbo moves as it shall. Can kill the engine if that is stuck. 
 

i think impeller is in the stern drive on these

Thanks!   

Are they easy to clean manually?  

I saw a picture of one where all the holes were clogged up with shells, is it just a matter or removing the bolts and taking it out, or do I need to drain the system?

 

Picture below shows there's.only 4 bolts to remove.

 

 

[Bitteliten]

Have not done it myself. I would have opened up, let the cool aid drain in a bucket, clean the cooler, locked it abd boltet it up with new seals, and filled cool aif. 
 

i think there are lids on both sides of the cooler. 
 

I had done that before i checked the impeller to see if that fixed it. 
 

alternative is acid cleaning, which most likely is easier and more effective since you will treat the entire system 

 

mechanical fixing tends to lead to new challanges like broken bolts or bad sealings… ;-). Murphy’s law is higly present on boats….
So I would have looked into the acid path first, most likely using this

https://seatronic.no/systemrens-1-liter/

 

Redigert 10.April.2023 av Bitteliten (see edit history)

[Jens_P]

Since the problem disappeared after engine shutdown, this appears to be a loose object in the raw water circuit. Could even be a piece of plastic that has covered the water intake in the stern drive that has fallen off while engine was stopped.

 

Faulty rubber impeller might be a problem. The pump is found inside the sterndrive. Checking or replacing means that you have to split the sterndrive to gain access. This is not the first component I would have checked.

 

A well known problem is the heat exchanger getting clogged as shown in your picture. This problem builds up slowly and will not disappear just by stopping and starting the engine.

 

Redigert 10.April.2023 av Jens_P (see edit history)

[Swingswong]

Not all drives has the impeller built in. 
What drive do you have?

[Jens_P]

Merc 1.7 dti is standard delivered with alpha one gen 2 and waterpump in the sterndrive. If deliverd with gearbox for pop.shaft waterpump is mounted on egine, but this is a rear combo.

[Theguy]

On 4/10/2023 at 4:31 PM, Jens_P said:

Since the problem disappeared after engine shutdown, this appears to be a loose object in the raw water circuit. Could even be a piece of plastic that has covered the water intake in the stern drive that has fallen off while engine was stopped.

 

Faulty rubber impeller might be a problem. The pump is found inside the sterndrive. Checking or replacing means that you have to split the sterndrive to gain access. This is not the first component I would have checked.

 

A well known problem is the heat exchanger getting clogged as shown in your picture. This problem builds up slowly and will not disappear just by stopping and starting the engine.

 

thank you jens!

 

ive decided to do one of two things, either remove the heat exchanger and clean the tubes manually, or use systemrens to clean it.

however, im unsure how to remove the heat exchanger, i see there is a thermostat at the front, and what appears to be 4 bolts holding the heat exchanger in place. do i just unscrew those bolts, pull it out and start cleaning it? and if so, do i need to buy new gaskets to replace the old ones?

 

otherwise, theres systemrens, but im unsure how to fill that.

 

i know this is probably basic stuff, but i really dont want to mess something up so any advice or tips on how to do this would be appreciated :-)

 

 

 

[HiWard]

Theguy skrev for 3 timer siden:

thank you jens!

 

ive decided to do one of two things, either remove the heat exchanger and clean the tubes manually, or use systemrens to clean it.

however, im unsure how to remove the heat exchanger, i see there is a thermostat at the front, and what appears to be 4 bolts holding the heat exchanger in place. do i just unscrew those bolts, pull it out and start cleaning it? and if so, do i need to buy new gaskets to replace the old ones?

 

otherwise, theres systemrens, but im unsure how to fill that.

 

i know this is probably basic stuff, but i really dont want to mess something up so any advice or tips on how to do this would be appreciated :-)

Your options depend on two things: if the heat exchanger is blocked by bits of impeller for example, systemrens won’t do anything for you. If however, the heat exchanger is blocked by deposits, systemrens might help.

 

I don’t have your engine, but remember that you’ll drain the coolant side of the heat exchanger if you remove it. On my engine, the heat exchanger is mounted bottom starboard on the engine and it’s a pita to remove and reattach the hose clamps and hoses.
 

I would try systemrens first, it’s not that expensive, just remember to remove any anodes first. I plan to fill my heat exchanger with systemrens via the flush port on my engine and let it sit for a while as preventive maintenance.

[Jens_P]

I have never removed the matrix, only endcover. Gasket on endcover is rubber o-ring, usually it can be used again. It is one anode in each end of heat exchanger. "Systemrens" will eat them if not removed.

Redigert 15.April.2023 av Jens_P (see edit history)

[Theguy]

Thanks Jens, I removed the cover and found this (image)

 

Is there a water inlet on the drev I need to check too in case it's blocked?

[Theguy]

1 hour ago, Jens_P said:

I have never removed the matrix, only endcover. Gasket on endcover is rubber o-ring, usually it can be used again. It is one anode in each end of heat exchanger. "Systemrens" will eat them if not removed.

 

[Theguy]

I'm not sure if my other post git posted, so here it is again:

 

The image shows how the heat exchanger looks, I'll clean it out with pipe cleaners, and then figure out the systemrens bit.

 

Is there a water inlet on the drev that needs checking too to see if it's blocked?

 

I saw both anodes, so I know what to remove. Do I just replace them with normal bolts while the systemrens does its thing?

Redigert 15.April.2023 av Theguy
Forgot a line (see edit history)

[Jens_P]

Theguy skrev for 5 timer siden:

Is there a water inlet on the drev that needs checking too to see if it's blocked?

Here: Then inlet in drive an the internal pipe that goes 10-15 cm upwards to the water pump.

Use somthing in plastic so you don't damage the paint. I prefer a cable tie that is about 20cm long.

 

 

When removing anodes, you kan use 1/2 inch blindplug from a plummer (or Jula or Biltema). 

 

 

 

[Theguy]

10 hours ago, Jens_P said:

Here: Then inlet in drive an the internal pipe that goes 10-15 cm upwards to the water pump.

Use somthing in plastic so you don't damage the paint. I prefer a cable tie that is about 20cm long.

 

 

When removing anodes, you kan use 1/2 inch blindplug from a plummer (or Jula or Biltema). 

 

 

 

Perfect, thank you so much!