My old Vega approx 1978 has MD7a engine which I believe has blown rings or worse. It runs but chuckes out white smoke in huge amounts plus fuel and alo fuel from air filter as well as exhaust. High rev and it feels like its pinking. It starts ok though! It is booked with boat yard to repair as apart from replacing filters, oil servicing injectors etc is not something I feel competant to carry out myself, but trying to find if anyone has parts or complete working engine they might like to sell me?
VOLVO PENTA MD7A
- Thread starter derek reynolds
- Start date
Derek, before you by new or replace, consider that rings and gaskets are
approx $1000 (Canadian). My mechanic charged me 20 hours at $50/hour to
rebuild. Bearings are so overbuilt, they do not usually require
replacement. Rebuilding injector pump and injectors is another $1000
CDN parts and labour at a special shop. The engine is easy to remove
and reinstall yourself if your yard has a crane. Trevor (V2915)
PS Engine runs like new now.
________________________________
From: AlbinVega@yahoogroups.com [mailto:AlbinVega@yahoogroups.com] On
Behalf Of derek reynolds
Sent: May 28, 2009 3:38 PM
To: AlbinVega@yahoogroups.com
Subject: [AlbinVega] VOLVO PENTA MD7A
My old Vega approx 1978 has MD7a engine which I believe has blown rings
or worse. It runs but chuckes out white smoke in huge amounts plus fuel
and alo fuel from air filter as well as exhaust. High rev and it feels
like its pinking. It starts ok though! It is booked with boat yard to
repair as apart from replacing filters, oil servicing injectors etc is
not something I feel competant to carry out myself, but trying to find
if anyone has parts or complete working engine they might like to sell
me?
approx $1000 (Canadian). My mechanic charged me 20 hours at $50/hour to
rebuild. Bearings are so overbuilt, they do not usually require
replacement. Rebuilding injector pump and injectors is another $1000
CDN parts and labour at a special shop. The engine is easy to remove
and reinstall yourself if your yard has a crane. Trevor (V2915)
PS Engine runs like new now.
________________________________
From: AlbinVega@yahoogroups.com [mailto:AlbinVega@yahoogroups.com] On
Behalf Of derek reynolds
Sent: May 28, 2009 3:38 PM
To: AlbinVega@yahoogroups.com
Subject: [AlbinVega] VOLVO PENTA MD7A
My old Vega approx 1978 has MD7a engine which I believe has blown rings
or worse. It runs but chuckes out white smoke in huge amounts plus fuel
and alo fuel from air filter as well as exhaust. High rev and it feels
like its pinking. It starts ok though! It is booked with boat yard to
repair as apart from replacing filters, oil servicing injectors etc is
not something I feel competant to carry out myself, but trying to find
if anyone has parts or complete working engine they might like to sell
me?
Seems like a young engine to be replacing it.
Has it seen a hard life?brbrThought my engine was messed up when I bought the boat. Could only go 2.5 knots before the thing started blowing black char lilly pads out the back.brbrAfter going all over that boat engine, and finding nothing very out of line... discovered it was the propellor. Way over propped by the previous owner. brbrI am somewhat dissapointed in all you vega experts that you didn't spot my problem right off. This is my first real boat and my first diesel engine.brbrBut anyway, my point is that you may not want to toss the engine first off.Make the mechanic give you a compression reading on your cylinders at least, if you think your rings are gone.brbrCould it be a timing issue?brbrCheck ur prop.... also barnacles on the prop will look like an engine problem if you are a beginner (ie. see above). Same as being overpropped.brbrdirty injectorsbrbrfuel pump timingbrbrI would think there is lots
to look at before you toss the engine.brbrroy
Has it seen a hard life?brbrThought my engine was messed up when I bought the boat. Could only go 2.5 knots before the thing started blowing black char lilly pads out the back.brbrAfter going all over that boat engine, and finding nothing very out of line... discovered it was the propellor. Way over propped by the previous owner. brbrI am somewhat dissapointed in all you vega experts that you didn't spot my problem right off. This is my first real boat and my first diesel engine.brbrBut anyway, my point is that you may not want to toss the engine first off.Make the mechanic give you a compression reading on your cylinders at least, if you think your rings are gone.brbrCould it be a timing issue?brbrCheck ur prop.... also barnacles on the prop will look like an engine problem if you are a beginner (ie. see above). Same as being overpropped.brbrdirty injectorsbrbrfuel pump timingbrbrI would think there is lots
to look at before you toss the engine.brbrroy
Hi Derek
Be careful not to spend too much on the old MD7A. I know you had an overheating problem so could be "cream crackered"..
Any advice needed then give me a bell, you have my numbers...
Cheers
Stevie B
Be careful not to spend too much on the old MD7A. I know you had an overheating problem so could be "cream crackered"..
Any advice needed then give me a bell, you have my numbers...
Cheers
Stevie B
Hi Steve,
Thanks for advise. Plan to get basic diagnostic if pos, if its hundreds ok, if its more I'll ditch. Could you give me tel and email of chairman you said would fit beta if I go that way. Also if you supplied any discount for cash? Derek
Thanks for advise. Plan to get basic diagnostic if pos, if its hundreds ok, if its more I'll ditch. Could you give me tel and email of chairman you said would fit beta if I go that way. Also if you supplied any discount for cash? Derek
Hi Derek
Contact me off Group please. steve@...
Mike Freeman's email address: mike@...
Cheers
Steve B
Contact me off Group please. steve@...
Mike Freeman's email address: mike@...
Cheers
Steve B
Hi all. I have a bit of a problem with my Volvo MD7a circa about 1978 engine. thought it was head area. I was getting masses of white smoke and fuel from exhaust as well as engine oil in engine well. Have had head ground. New head gasket, injectors serviced.Fitted new springs to valves and rubbed valves in and general decoke. It doesn't help. Low revs small white smoke from exhaustalong with sea water cooling.. Middle revs more of both. Upper revs more but then engine races and is difficult to stop. Any suggestions. Thinking it might be a fuel governer if there is one in fuel pump? If it is can anyone sell me one cheap? I have 90% of mD6a in garage anyone interested? Based West Sussex uk
Derek,
What color is your engine oil? If there is too much oil in the sump, and it looks like a mix of oil and milk, there is water in it.
The cheap and easy cause is broken seals on the impeller (sea water pump) shaft. More expensive is cracks in the engine block or cylinder head :-(
A broken head gasket could cause this too, but massive leaks are rare.
If there is too much oil (and water) in the sump (crankshaft housing), oil mist is blown into the air filter via the vent in the rocker cover, making the engine race as it runs on both diesel and lube oil.Cheers
Ulf
What color is your engine oil? If there is too much oil in the sump, and it looks like a mix of oil and milk, there is water in it.
The cheap and easy cause is broken seals on the impeller (sea water pump) shaft. More expensive is cracks in the engine block or cylinder head :-(
A broken head gasket could cause this too, but massive leaks are rare.
If there is too much oil (and water) in the sump (crankshaft housing), oil mist is blown into the air filter via the vent in the rocker cover, making the engine race as it runs on both diesel and lube oil.Cheers
Ulf
Derek,
My engine had the leaking water pump seal Ulf described too,and at first I thought it was a leaking head gasket. Steam came out of the oil fill hole after the engine warmed up, and the breather hose was full of mayonnaise.
There's a bleed hole on bottom of the pump beneath the center of the shaft. The pump has two seals on the shaft - one on each side of the bleed hole. If a little sea water gets past the first seal, the water should drip out of the bleed hole, and the second seal would protect the engine from water incursion. I didn't have any water leaking out my water pump, so I thought it was good to go, until I checked the bleed hole and found it clogged up and allowing the seawater to go right past both seals and in to the crankcase. I hope that's the problem, because over hauling the water pump is easy.
Good luck,
Patrick________________________________
From: ulf.raknes ulf@...
To: AlbinVega@yahoogroups.com
Sent: Friday, June 19, 2009 1:57:26 PM
Subject: [AlbinVega] Re: VOLVO PENTA MD7ADerek,
What color is your engine oil? If there is too much oil in the sump, and it looks like a mix of oil and milk, there is water in it.
The cheap and easy cause is broken seals on the impeller (sea water pump) shaft. More expensive is cracks in the engine block or cylinder head :-(
A broken head gasket could cause this too, but massive leaks are rare.
If there is too much oil (and water) in the sump (crankshaft housing), oil mist is blown into the air filter via the vent in the rocker cover, making the engine race as it runs on both diesel and lube oil.
Cheers
Ulf
My engine had the leaking water pump seal Ulf described too,and at first I thought it was a leaking head gasket. Steam came out of the oil fill hole after the engine warmed up, and the breather hose was full of mayonnaise.
There's a bleed hole on bottom of the pump beneath the center of the shaft. The pump has two seals on the shaft - one on each side of the bleed hole. If a little sea water gets past the first seal, the water should drip out of the bleed hole, and the second seal would protect the engine from water incursion. I didn't have any water leaking out my water pump, so I thought it was good to go, until I checked the bleed hole and found it clogged up and allowing the seawater to go right past both seals and in to the crankcase. I hope that's the problem, because over hauling the water pump is easy.
Good luck,
Patrick________________________________
From: ulf.raknes ulf@...
To: AlbinVega@yahoogroups.com
Sent: Friday, June 19, 2009 1:57:26 PM
Subject: [AlbinVega] Re: VOLVO PENTA MD7ADerek,
What color is your engine oil? If there is too much oil in the sump, and it looks like a mix of oil and milk, there is water in it.
The cheap and easy cause is broken seals on the impeller (sea water pump) shaft. More expensive is cracks in the engine block or cylinder head :-(
A broken head gasket could cause this too, but massive leaks are rare.
If there is too much oil (and water) in the sump (crankshaft housing), oil mist is blown into the air filter via the vent in the rocker cover, making the engine race as it runs on both diesel and lube oil.
Cheers
Ulf
Hello boys , anyone heard of a stainless steel aftermarket exhaust manifold for MD7a ? Or maybe any manufacturer known for bulding st.steel manifolds ?