Blown head gasket or cracked block?

[MarkTheBike]

Hi all

OK, I accept some of you will roll your eyes at my naivety but I have a horrible feeling that I've done something nasty to my MD2030D (B34/2001). It quite likely there were symptoms that I should have spotted but didn't. Like many on here I've been reading about, I suddenly had the temp warning go off today. It was after a short period (5-10 mins) of 3/4 throttle. I'd already slowed down to tick-over as I was approaching the lock to our marina and was quite surprised to hear it. Fortunately, we were 20m away from a different marina's pontoon so was able to quickly tie up and get the engine off. I let it cool for 15mins and carefully took off the filler cap. No water visible. It had been losing a little recently, perhaps a cupful a month, but I've just replaced the impeller pump seal as it had been weeping so thought it was fixed. In doing this, I'd taken out the tubes from the exchanger. Refilling took a lot of water and I wondered if I'd not resealed the tubes properly (my thinking being that I could be losing coolant into the exhaust). Eventually, it maintained the water level in the header so I went to try starting. We only had 3 mins of tick-over motoring to get back to our berth so I reckoned that leaving the filler cap off and someone ready with a bottle of water to top up, we'd get back. However, after pre-heating, I pressed the button but the starter was barely able to turn the engine over a couple of times. Normally, it starts straight away easy as pie with no smoke so something major was wrong. The only thing I can think of has to be a head gasket or cracked block and, thanks to my liberal use of the water bottle, a cylinder or two full of water. Great.

As an aside, I can't fault my marina, Sutton Harbour. At two minutes notice, they sent out the dory to get me through the lock and back into my berth. Very kind and helpful indeed. Great bunch of guys.

OK, now for the questions to any of you with engine experience -

1. does this sound like a head gasket, or, Heaven forbid, a cracked block?

2. if it's a cracked block, is it repairable or must it be replaced (can you even get recon Volvo blocks?)

3. does this sound like a water-flooded cylinder and if so, what is the likelihood of internal damage when trying to start (bearing in mind it only turned over once or twice before being turned off)?

4. is there an easy way for me to find out if there's water in a cylinder? I've got spanners and sockets, etc. but not much working knowledge of fixing marine diesels. Could I take out the injectors, stick in a bit of string and see if it comes out wet?

All thoughts are welcomed. I'm in Plymouth - anybody recommend any engine guys round here? There's always Marine Engineering (Volvo) but I'd rather not if I can avoid it...

Thanks in advance...

[dawntreader]

Last year I accidently siphoned (fresh) water into my engine. It would not even begin to turn over - water is not compressible. As yours is turning I doubt very much that you have that issue. If you are not overly mechanically minded I suggest you get someone in to assist. I was able to strip out the injectors and the water was easy to spot and clear. I am in MDL Brixham and the marina here have a list of local people who provide different services - I expect you should be able to get a similar list in Plymouth in order to find an engineer.

As we all know too well, 'Volvo Spares' is an anagram of 'very expensive' 

[MarkTheBike]

Hi Dawntreader

OK, that gives me a slight smidgeon of hope. It's not that I mind getting my hand dirty (I rebuilt a Landy petrol engine a while ago) but I have no experience with diesels. I know the rough theory but not the practical side. I have no problem getting someone in to do it but would really like to investigate beforehand to find out what I'm faced with.

Cheers

[dawntreader]

OK, diesel engines are much the same physical structure as petrol except they use compression to ignite the fuel rather than a spark. Apart from the fuel system other component parts are much the same too. The injectors can be removed much the same as spark plugs too but don't take them apart and once out handle very carefully as the needle (bottom of unit) must be protected. Mine were sealed into the block with loctite or similar and difficult to remove. Check your oil - blown head gaskets (commonly but not always) breach the gap between the oil and water channels in the engine and the effect of this is that oil and water mix. This emulsifies the oil and it will show on the rocker box cover as white mush. Have you checked the oil level? I would suspect that overheating (water) is more a consequence of low oil pressure rather than the cause of your problem but then you should have seen the oil pressure warning light first. At this stage I wouldn't suspect a cracked block either. That is a catastrophic failure and would manifest itself with lots of noise as well.
Before you start to dis-assemble the fuel pipes and injectors you should have a look at the workshop manuals. There are links to the workshop manuals for my engine on this site and I found them very useful but I haven't looked for yours - perhaps someone can help? Failing that I can point you to the section on removing injectors in the D1-30 manuals which I suspect would be similar if not exactly the same procedure.

[IslandAlchemy]

I would suggest that the first thing to do is whip the injectors out and have a look in the holes for water in the cylinders (you can get little endoscope cameras on ebay for about £10, which are great for looking into dark holes.

If you have water in there, then get the head off.  Even if you see a break in the head gasket, it's worth getting the head pressure-tested and skimmed while you have it off the engine.  If you tried to start it with water in, you may well have bent a con rod. You can get a quick idea of this by turning the engine by hand and measuring the maximum piston heights (with a dti). If one of lower than the others, it's a sump off job I'm afraid.

If there is no water in the cylinders, try turning the engine by hand and see how much resistance there is (shouldn't be much at all with the injectors removed.  If there is a bit, put some oil down the bores and see if that makes it easier.  If it does, then you might have damaged the rings and liners, in which case, it's head off, and have a look in the bores to see if you can see any scaring.

[CRYSTAL]

Hey there.  Try this attached d1 30 installation manual.  Hope it helps. Part A is somewhere in this forum. Good luck!

Dawntreader,
if I may ask, how did fresh water get into ur engine?  And avoid similar incident :-)

Regards

[Symphony]

From what you are describing it is the fresh water system that is the problem. Normally freshwater would not get into the cylinders as it is a closed circuit, unlike the sea water which injects into the exhaust manifold and can then get back into the cylinders. For fresh water to get in it is either head gasket, cracked block/head or failure in the heat exchanger allowing freshwater to escape into the seawater circuit.

As suggested, remove the injectors as a first step.

[dawntreader]

Symphony: I think you are confusing my previous problem with the one MiketheBike now has - he is not sure what the cause of his problem is yet - it could be water or not in the pistons and he needs to look. If there is water in the piston chamber it will be easily noticed once the injectors are removed. Also it will shoot out (all over a wall  ) if you turn the engine over.

Crystal: I was flushing the engine and cleaning the intake to the star drive. I do this using a jerry can on deck which is continuously fed by hose from the fresh water supply. I feed the engine using a separate hose down to the raw water intake on the pre-filter. I also decided to change the oil once finished flushing as the engine was hot but I did not remove the fresh water feed. Although the engine was not running, I suspect the water syphoned past the impellor, through the heat exchanger and into the exhaust pipe. The exhaust pipe has a swan neck and so would have back-filled. Water would then get into the engine through the exhaust elbow - into any cylinder with an open exhaust valve.
After changing the oil, the engine would not turn over and I realised what had happened. I was able to remove the injectors and cleared the water in the cylinder by turning over the engine a few times. It's amazing how far it spurts
The engine oil was not contaminated as the piston rings kept the cylinder sealed and I got away with it. I now remove the fresh water feed once the engine has been flushed - lesson learnt 

[MarkTheBike]

Hi all

Well, thanks for all the thoughts; I obviously need to get the injectors out as a first task and turn the engine over to see if water comes out. Dawntreader - your last post gave me a thought; perhaps I actually had unwittingly filled the exhaust with fresh water and turning the engine over sucked some back through the valve into a cylinder. Not very hopeful but maybe it's not a head gasket or block? Well, I'll be down there tomorrow or Wednesday with a bag of spanners and report back in due course.

Thanks again, everyone. I don't think I've ever come across another site quite like this for so many active, helpful folks willing to offer advice. It is really appreciated by noobs like me.

[MarkTheBike]

Quick update:

Found a forum from the States where a chap had exactly the same problem - turned out there was a 1/2" hole corroded between the exchanger and the manifold. In my case, that would explain a) the faint glug-glug I could hear but assumed was the cavities filling up, and b) where all the water had gone - into the exhaust - it wasn't due to a badly fitted tube bundle. I don't have a little camera but I do have a small light and a dentist's mirror so I'll take out the tubes and see if I can spot any black holes.

[Anthony]

Check the oil dipstick.
A cracked head or blown head gasket allows cooling water into the sump revealed by the level being way too high and the oil emulsified or whitish compared with the usual honey or black ( depending on the time between oil changes).

[MarkTheBike]

Hi Anthony

I can't believe I hadn't mentioned it before - it was the first thing I did after the engine failed to restart. Although a little dirty after a season's use, the oil was not emulsified, black or sludgy and was at the same level on the dipstick as my morning's pre-sail checks, implying that there's probably no water ingress. The more I think about it, the more I'm sure it's a corroded heat exchanger (+ all the collateral damage, of course).

OK, I've been looking around but have not found any info on how to take out injectors for a 2030. I've got full sets of ring and open-ended spanners, decent sockets and torque-wrench. I now appreciate how delicate injectors are, so any hints or links would be very welcome. I'm heading down again tomorrow (Wed).   

[dawntreader]

I've looked at the view of the fuel system on MarinePartsEurope and, although slightly different, I suggest you read up the manual for the D1-30 (linked in a post above) as it will give the procedure to remove the injectors. It should only take about 30 mins. Take a camera too - they tend to have better memories of what it looked like before you took it apart . You may need a bar on the socket set - mine were very tight when I tried to remove them.
What are you going to test for? I doubt that there will be any water in the cylinders from your comments made earlier. There is nothing else to see. The only thing that may help is to turn it over and see if it goes fast - if not you will need to get an engineer to look at it.

[MarkTheBike]

Hi Dawntreader

I still feel that it's a distinct possibility there's water in one or more of the cylinders. I think, if there is a hole from the header into the exhaust, that the excess water I added would have run into the exhaust pipe and into any cylinder that had its exhaust valve open. Mind you, it's all conjecture at the moment but thanks for your point about taking a tommy bar as well. I have read in several places that the injectors and glows are Loctite'd in place.

Edit: Yes, thanks for the hint about the camera, good idea. I had given the manual a skim through but not enough. Having gone back to it, I found the bit you're referring to. Seems pretty straightforward - nervy on the first one, easier thereafter. Also, going back to your post #7 to Crystal - you mention that there is a Swan Neck in the system that can lead to back-filling. I have the same so if this backfilling is allowed up to the level of the exhaust valves then one or more may be wide or just starting to open/close; just a crack would be enough, I expect. Well, whatever it is, I'll know soon enough...

[telford_mike]

Hey there.  Try this attached d1 30 installation manual.  Hope it helps. Part A is somewhere in this forum. Good luck!

Dawntreader,
if I may ask, how did fresh water get into ur engine?  And avoid similar incident :-)

Regards

Can anyone point me at part A of that workshop manual please?

[CRYSTAL]

Try this link
http://www.polardcmarine.com/cms/support-2/product-manuals/

BR

[telford_mike]

Try this link
http://www.polardcmarine.com/cms/support-2/product-manuals/

BR

Thank you sir!

[MarkTheBike]

Dear all

Well, I appreciate that this thread has been sleeping for quite a long time, and I'm sorry that it's taken until now to remember it, but I thought I'd wind it up with the eventual outcome. The hazarded guess that it might be a hole between the H/E and the manifold turned out to be correct. In topping up the header, the water had been filling the exhaust and had entered 2 out of the 3 cylinders via the valves. What I think happens is this - when the hot raw water exits the H/E, it passes into the exhaust elbow, which has a jacket around it. The water fills the jacket, cooling the exhaust and is then passed into the exhaust gasses at the end of the sleeve. Pic4901 shows the rubber connector attached to the elbow. Over time, the hot raw water erodes a hole under the rubber connector and into the exhaust (Pic4918). This doesn't cool the exhaust correctly, causing the back of the H/E to overheat and accelerating corrosion at the back of the manifold, in the dead space under the tube bundle. Therefore, you suddenly have coolant draining into the exhaust, just above the valves and already have hot raw water in the exhaust but at the top rather than half way down. Anyway, the result was a mess. Thankfully, I've found a really good one-man band (Tony Hole Marine, Plymouth), who came and stripped down the whole lot (pic4915). He arranged for the head to be checked (Paul Inch Engineering), and ordered a new manifold and elbow + bits.  He also checked and cleaned the cylinders and de-glazed them. The head was OK but the valves were shot so they were replaced with new. Once the manifold and elbow arrived, Tony returned and put the whole lot back together again. She's been running beautifully ever since - starts first touch of the button every time, much quieter and completely smoke-free. Tony and his lad took a 9hr day to strip it and a 10hr day to clean and rebuild. The manifold was in excess of £1K (not sure about the elbow but probably not cheap), the head+valves was about £250ish, £175 for the gaskets, + all the filters, oil, a blown pressure switch and the whole lot came to less than £1900. I can't fault that and I'd recommend him unhesitatingly. Top bloke. Happy to supply contact details for anyone interested. Hope this might be of help - sorry about the wait.

Cheers