MD1- Hard to start.

Joined
13 Aug 2005
Messages
850
Location
Bangor, County Down
Visit site
I managed to obtain a replacement cylinder head and ground the valves in. I could not remove the barrel because one of the bolts was badly rusted. I also poured some STP ? Diesel treatment down the bore to try to release possibly sticky rings. When I re-assembled the engine there was very low compression but I used some of the dreaded Easy Start and it eventually fired. I gave the engine a good run and noticed that on stopping it "kicked back" indicating compression I think. After letting it sit for a while I found that it would start easily,but after sitting for a week (launch day!) I had to go through the whole rigmarole again. Any suggestions? I tried to search for the "squirt oil in the inlet manifold" thread but cannot find it,could someone repeat it for me?
Thanks, Peter.
 

Bilgediver

Well-known member
Joined
6 Jun 2001
Messages
8,083
Location
Scotland
Visit site
I tried to search for the "squirt oil in the inlet manifold" thread but cannot find it,could someone repeat it for me?
Thanks, Peter.
***************************************************

Easy start will kill it....If more than a wee drop is used you risk lifting the head and stretching the head studs. If this happens then crap blows into the joint and you are on your way to grooving the head gasket and the head or block.

The best way is to remove the air inlt silencer/cleaner and with an oil gun squirt a few squirts of engine oil in and the wind over decompressed.

The engine will fire immediatly....No cranking and cranking.

Sounds like you didn t do a good enough job on the valves and maybe some worn rings.


Do you have a visible breather on the engine or was there a breather fitted internally into the push rod space.
 

bluedragon

Active member
Joined
7 Apr 2004
Messages
1,773
Location
Cardiff Bay
Visit site
We always start our Sabb 8 with oil injection, but it had such a system designed into the engine originally for cold-start anway. It possibly is worn rings / bores in your case, and if you don't run it for a time any oil in the bore just drains away and you lose compression for starting. We give ours six squirts from an oilcan and it fires immediately. The oil goes into the inlet port via a small nipple on top of the engine. I don't know the best way to do that on your MD1 engine, but that's the principle. If the engine is otherwise OK, is reliable and re-starts when warm, then keep it going! I feel too many (good) old engines are scrapped because they don't start as easily as they once did. There may be years of life left in it yet.
 

charles_reed

Active member
Joined
29 Jun 2001
Messages
10,413
Location
Home Shropshire 6/12; boat Greece 6/12
Visit site
[ QUOTE ]
From what you say it's time for a new engine.Sorry.

[/ QUOTE ]

Maybe, he's not got the cash to splash? Obviously you have.

If the engine drives the boat and no oil is leaking out of the rear-seal, it's worth persevering with. When blow-past is pressurising the sump, then it's time to rebuild or re-engine.

As suggested, lube oil into the air-intake to get the compression up again, when starting from cold.
If it's not starting when hot, have the injector out and take it to a diesel injector specialist (few and far between) and have them re-calibrated. If you can't find them in Yellow Pages, try asking the mechanic of a big logistics company. It should only cost a few £ and is probably the cause of the problem.

PS the MD1 is single-cylinder isn't it; I, thank God, have managed to avoid owning a Volvo marine engine, though I have had a couple of Volvo cars (which I would swear at, but not by).
 

Bilgediver

Well-known member
Joined
6 Jun 2001
Messages
8,083
Location
Scotland
Visit site
John the breather is in the push rod space, Peter

**********************************************

ok Peter

Well in that case start the engine the way I have advised and maybe in the course of the season the valves will bed in...Just watch your exhaust especially when under load as in your engine this also gives an indication of ring condition.

If the rings and bores start to leak excessively then you will have a grotty oily black exhaust resulting from oil from the push rod space being drawn through the interior breather by the heavy breathing....

Even when you get to this stage don t give up!!!!!! On a dockmates boat we just deglazed the bore with a Sears triple stone deglaser and plugged the interior breather (a grease nipple fits) We then fitted an exterior breather from the wee round plate on the back to the inlet silencer and the engine ran another five years that I know.

I did the valves as well. Please note that where on a petrol engine you might get away with lots of grinding in,however in the case of diesels this can easily produce wider seats than is good. The valve and seat angles in these diesels differ by about 1/2 degree
Any good motor machine shop can do this with grinding equipment however when I do these dockside repairs I use a Pickavant seat cutter for the BMC 1000 engines as from Halfords and then stick the valves in a lathe and do the seats to the right angle.

If you can find someone with a lathe this is better than excessive grinding but a light touch is required. Just a minor amount of lapping should be needed. It is all to easy when grinding away to get past in the valve guides so take care.

We have a few of these old engines around here and in Canada that have given years of service after being breathed on.
 

pikeyrm

New member
Joined
30 Sep 2007
Messages
283
Location
southampton, uk
Visit site
sounds like head gasket again. i had same problem recently.
or could be that the head bolts was not tightened up enough. My advise would be not to go all the way to the 80 psi that is in the book but go to atleast 60 psi. and do this in stages of 5 or 10 at a time
 

Stemar

Well-known member
Joined
12 Sep 2001
Messages
22,642
Location
Home - Southampton, Boat - Gosport
Visit site
This engine must be getting on for 40 years old. It was one of the engines that got Volvo their original good reputation, but it must be getting pretty tired by now. A squirt of oil in the inlet manifold will probably help, but parts for a complete rebuilt are no longer available, so I fear it's time to start saving for a replacement.

I had one on Jissel and it pushed her along at all of 2 kts when I bought her. An expensive refurb of injector and pump got her up to 4 knots, but then the engine was pumping the oil out into the bilges. I discovered that the time to empty the sump was about 10 minutes less than that from Hardway to Newport, and it was time for a change...
 

Topcat47

Well-known member
Joined
2 Jun 2005
Messages
5,032
Location
Solent, UK
Visit site
There is a cold start button at the back of the engine. I can't remember what it does as I junked my MD1 about 8 years ago, but it worked when pressed down. Have a hunt round your engine and give it a try before ripping the head off again.
 

30boat

N/A
Joined
26 Oct 2001
Messages
8,558
Location
Portugal
Visit site
That remark is agressive to say the least.As was said above this is an engine that borders on 40 years of age.There are no miracles and the owner may throw as much money at it as he pleases and in the end he will have to re engine anyway.The fact that there are studs rusted solid is a very good indication of the (bad)condition of this engine .
You won't do this owner a service by encouraging him to keep mending the thing and spending good money in the process when this capital could be put to better use in a new or newer engine.
I've been down that alley and wish I'd got my Beta instead of having a 26 year old Bukh rebuilt.
 
Top