Perkins 4.108

[Soundings]

Help please! Coming back from Barton Broad this evening the Perkins 4.108 started to overheat. The first was sign was the warning buzzer at the helm and the temp gauge up around 100 degrees. Dropping back the revs brought the heating under control but we had to limp home on tick-over. What was in evidence was the lack of water being pumped through the engine – it was erratic at best but once we got back to the mooring there was nothing at all.

As such the boat is currently out of commission so I need a good guy to fix it for me pdq. It could I guess be either a blocked filter (if I only knew where to look) or a dead pump or something else. I’m no engineer so I need some help/guidance please.

All help will be appreciated.

Big thanks

Colin

[Mowjo]

Colin! I'd say the first thing to check is your weed filter, the fact you don't know where it is tells me it's never been cleaned out, and with all the weed thats been about this last week or two it's possible yours is blocked, you should have a pipe running from your water pump to a stopcock in your bilge, it should have either a lever or a wheel shutoff, turn it fully off and on the top of the filter there should either be a cap held on with two wingnuts of it will be a screw cap, remove it and inside there should be a gauze filter, just take it out clean it and get all the crap out, then reverse the process to put it back together, and rememer to turn the Stopcock back on, start your engine and look out the back of the boat, if you have plenty of water coming out of your exhaste, that was the problem, if not and your only getting a dribble of no water at all then it's probably your impellor that needs changing, it's not a hard job to do but you need the right impellor, you don't say where your moored so I can't help you with someone to do it for you, but if your on the Ant you have David at Broadsedge, Clive at Richardsons, Jason at Ludham Bridge and Moonfleet, I won't be near my boat for a couple of weeks so I can't take a look at it for you, but knowing this forum someone here will be able to help you out,,

Regards Frank,,,

Ps, just as an addy get someone to show you how to check your weed filter, it's a very important check and if not done you could blow a head gasket or worse seize your engine up, if I'm out on a trip I check mine every time I moor up, a bit excesive but I say better safe than sorry,,

[jillR]

couldent find a picky of a weed filter so i attempted a drawing of mine.

yours may not look the same but the principle will be.

A - screw of cap ( if stiff, spray with penetrating oil rather than straining hull fitting)

B - stop cock

C - hull of the boat

D - pipe to engine

E - mesh lift out filter, inside.

[jillR]

just found this

http://www.asap-supplies.com/marine/hul ... -strainers

if you need an impeller, peachments of asap could help

[diesel falcon]

It,could look like the glass topped one on the right of the engine,

[Soundings]

Thanks to all for the advice. Found the filter and it is clear but water flow is erratic. Seems like a failed impella to me. Things are getting worse though as I have noticed white smoke coming from the exhaust and everything I have read seems to suggest that this is a cracked head. What do you think?

If head is cracked is it worth replacing (the engine is over 20 years old) or should I bite the bullet and re-engine? What would the cost of a re-engine be? I'd probably go for a good recon.

[diesel falcon]

hi,

obviously without seeing it ,a complete engine swop seems a bit premature,it may be that the reason the engine overheated is that simply the head gaskets blown,or the lack of cooling water from the water pump has caused the gasket to go (more likely),in which case it,s a new gasket ,and to be sure a skim to the head,quickest is a recon head,less expensive than a full exchange?

all the best ,Trev

ps volvo pentaman may be along shortly!!

[Mowjo]

Is it white smoke or steam due to the lack of water???? If the Impellor has gone the little water that gets into the exhast will instantly turn to steam if the engine is hot, first thing I'd do is change that impellor and see if thats the cause before you go spending loads of money on a re-build,, it's pretty normal to chuck out a bit of white smoke on start up, but once the engine has warmed up it usualy clears, I think it's something to do with unburnt fuel when you start it up, mine does it for about 30 seconds before it clears,

If it's chucking out smoke after warming up the you may have a more serios problem, Jason at Ludham bridge has a good motto when it comes to old engines, he say's if it ain't broke don't try and fix it, If your anywhere near his yard pop in and see him, he's great on diesels and they are all really helpful there,,

Regards Frank,,,

[senator]

Although it is normal to fear the worst it very rarely is.

First off check your inlet fitting to ensure there is not a plastic bag over it or it is not full of leaves.

If that is clear check your oil for emulsification, (white) and your fresh water for oil, (scum around cap etc.) If either are present then head gasket is looking likely, do a block test to find out if you have exhaust fumes in the fresh water to confirm.

If not you are back to your cooling system, check all your hoses to see if any have delaminated and are reducing flow. change the impellor but read up first as you can do serious damage to your pump housing if you go in ham fisted.

[Soundings]

These are the checks carried out -

- Filters and inlets clear

- Impeller is ok

- No emulsification on dip stick or in oil filling area.

- White smoke present when engine was hot (and water not circulating properly). It only seemed to be in evidence when water was not circulating (circulaton erratic)

- Jason will have a look at the pump as that may be knackered.

Spoken to Jason, he does not believe in fitting new/reconditioned heads. He believes that on old engines everything wears together and if you replace something central like a head with a new one it just knocks out the bearings! His view is always re-engine and with a new one as you cannot get good recons these days. The cost of that is around £7000!! That is a lot of dosh and whatever happens here I know that eventually I will have to change the engine. Are there reliable rebuilds around?

Thanks

Colin

[diesel falcon]

hi,

silly this but is the stat opening??

[Soundings]

Stat is opening - good thought though

[senator]

It is still more likely that the head gasket has gone than the head so your £7k is a bit premature

[Soundings]

Hope ou are right. Jason believes a cracked head is on the cards as it is a Perkins 4.108 weakness.

[jillR]

i would have thought that 20 years is not old for a marine engine

they age much slower than a vehicle engine.

jill

[diesel falcon]

http://www.parts4engines.com/index.php? ... e5f462253b

http://www.parts4engines.com/index.php? ... cts_id=262

http://www.parts4engines.com/index.php? ... cts_id=336

I got bored so have been shopping for you!!

[Guest]

Spoken to Jason, he does not believe in fitting new/reconditioned heads. He believes that on old engines everything wears together and if you replace something central like a head with a new one it just knocks out the bearings! His view is always re-engine and with a new one as you cannot get good recons these days. The cost of that is around £7000!! That is a lot of dosh and whatever happens here I know that eventually I will have to change the engine. Are there reliable rebuilds around?

Thanks

Colin

I recently had my BMC engine rebuilt, I was advised by a number of people to get a new engine instead of a rebuild. A new engine would have cost at least £7000, probably a lot more.

The rebuild cost £3500 and the marina charged me another £750 to refit, add new pipes, new wiring and a couple of other bits and pieces. The total cost was £4250. I couldn't be happier with the engine now, it runs much better than ever before, has more power, doesn't emit clouds of smoke, even sounds different. Yes, I still have a 35 year old engine, all be it with a lot of replaced parts, but it has worked out a lot cheaper than buying new and will hopefully continue giving good service for many years to come. My rebuild was done by Calcutt Boats in Warwickshire, my engine was knackered and needed a total rebuild, which included a new injector pump and cylinder head.

[Guest]

My BMC overheated and it turned out to be weed stuck in the inlet to the strainer. I couldn't see the weed and the only way to remove it was pushing a rod down through the strainer and out the bottom of the boat (only works if you don't have some sort of strainer over the inlet under the boat).

[NeilB]

No Perkins but a nice supply of recon BMC's here -

http://www.calcuttboats.com/engines.html

[goodall_m1]

My BMC overheated and it turned out to be weed stuck in the inlet to the strainer. I couldn't see the weed and the only way to remove it was pushing a rod down through the strainer and out the bottom of the boat (only works if you don't have some sort of strainer over the inlet under the boat).

I had a similar problem last year when Eden Bridge tried to swallow some reed fronds that then blocked the inlet pipe. The pipe wasn't very easy to get to in order to put a rod down it. Perhaps one of those flexible drain cleaners might be useful...

[Soundings]

Thanks to you all for the help and support. Things, it seems, were not as bad as first thought. Jason and the boys looked at this today and found that weed had entered the cooler via a damaged inlet filter. Crud has been suitably removed and engine is apparently running now at a reasonable temp with no white smoke. Fortunately I have two water intakes and whilst the master was well and truly blocked the secondary at least let some water through; this probably saved the day.

Ludham Bridge Boatyard rules ok as does this forum

Good cruising all

Colin

[iocus]

On 11/07/2010 at 11:50, diesel falcon said:

hi,

obviously without seeing it ,a complete engine swop seems a bit premature,it may be that the reason the engine overheated is that simply the head gaskets blown,or the lack of cooling water from the water pump has caused the gasket to go (more likely),in which case it,s a new gasket ,and to be sure a skim to the head,quickest is a recon head,less expensive than a full exchange?

all the best ,Trev

ps volvo pentaman may be along shortly!!

Hi, apologies for the late involvement.

Was just browsing for Perkins advice when I came across your post. As I understand it, the Perkins manual for a 4.108 states that there is no tolerance for skimming the head? I think I have the same/similar issue as the OP, hence looking for advice re head skimming as I was surprised to find I'm not supposed to to skim the head? Thoughts?

[Smoggy]

You don't always have to skim a cast iron head, it's more an aluminium head thing as they warp so much easier when over cooked.

You can get the face clocked up and see it it's flat or not.

Edit: I am assuming cast iron head here as I've never had an old perkins apart but can't imagine otherwise for that age.

[Vaughan]

The 4108 was developed from the 4107, which had a habit of bending the head when overheated.  So the 4108 has a strengthened head with wider and stronger head studs.  The size of the head fixing nuts is almost the only way to tell a 4107 from a 4108, without actually measuring the cylinder bores.  All the same, the 4108 can still bend the head if it gets too hot.

Duffields in Norwich (who developed the Perkins MC42) could successfully skim the heads but they are no longer with us and I wouldn't know where to go to get it done now.

What is more likely is that the head has developed a small crack, which cannot often be seen without magnetic testing.  These cracks would allow cooling water to escape into the cylinders.  In my experience, the 4108 did not often blow a head gasket.  Hopefully your overheating problem is coming from somewhere else and can be easily fixed.  For instance, have you checked the rubber socks at the end of the heat exchanger and at the gearbox oil cooler, to see if they are blocked by debris which has got past the weed filter?  If you have hydraulic drive, definitely check the intake end of the drive oil cooler.

Raw water cooling systems will usually go to the gearbox oil cooler - and always to the hydraulic drive - before they go to the engine.

Edited October 18, 2022 by Vaughan
line added

[Smoggy]

55 minutes ago, Vaughan said:

to see if they are blocked by debris which has got past the weed filter?

Or a previously destructed impellor vane.