Removing thermostat housing on Volvo Penta 2002.

[eddystone]

Don't actually have the engine in front of me but from photos it looks like once the two bolts on the thermostat housing are removed, it's still held in place by the rigid pipe going to the elbow. Do you also have to remove the elbow or is there enough "give" in the likage to allow the thermostat housing to be lifted.

(Of course as it's the original engine on a nearly 30 year old boat, I realise I should be dumping it for a new engine even though it runs OK).

 

[paddywackcocker]

A sharp tap should make it brake seal.
The pipes on the 2000 series don't like being moved out of original plane and deffinetly replace with new seals, there are other ways to get round it but to stay with original always looks better to all concerned.
P

 

[eddystone]

I was looking at some photos of a 2002 for sale on ebay and the pipe from the thermostat housing to the elbow was straight. Flying visit to the boat yeaterday evening to collect a few things - noticed this pipe on mine has a "u bend" with a removeable section connected by short hoses and jubilee clips?

BTW there is a nut on the side of the thermostat housing - what is this for?

 

[VicS]

I was looking at some photos of a 2002 for sale on ebay and the pipe from the thermostat housing to the elbow was straight. Flying visit to the boat yeaterday evening to collect a few things - noticed this pipe on mine has a "u bend" with a removeable section connected by short hoses and jubilee clips?

BTW there is a nut on the side of the thermostat housing - what is this for?

The nut is a plug! It is where a nipple for a hose to the expansion tank would be fitted to an indirectly cooled engine.

A raw water cooled engine has straight pipe between the thermostat housing and the exhaust elbow. Indirectly cooled versions have two hoses, to and from the heat exchanger. A calorifier can also be fitted here. See recent discussions on this forum.


NB anode(s) are required when raw water cooled.

 

[KREW2]

The short answer is yes.
The pipe is fixed to the thermostat housing so don't force it up.
There is one small bolt securing the pipe to the elbow I think it is 10ml. Remove it, being careful not to lose the clamp washer type thingy that holds the pipe in, then the thermostat housing and pipe come off together.
No need to remove the elbow.

 

[eddystone]

The nut is a plug! It is where a nipple for a hose to the expansion tank would be fitted to an indirectly cooled engine.

A raw water cooled engine has straight pipe between the thermostat housing and the exhaust elbow. Indirectly cooled versions have two hoses, to and from the heat exchanger. A calorifier can also be fitted here. See recent discussions on this forum.

Well that's odd - mine is raw water cooled but the pipe to the elbow has a "loop" in it, almost like a syphon loop.

NB anode(s) are required when raw water cooled.

 

[VicS]

Well that's odd - mine is raw water cooled but the pipe to the elbow has a "loop" in it, almost like a syphon loop.

The parts diagrams just show a straight pipe.

is it a vented loop? has someone tied to install an anti siphon loop at that point ?

The antisyphon loop with this engine would normally be in the hose between the pump and the inlet to the perforated pipe in the cylinder head IIRC

 

[vyv_cox]

The parts diagrams just show a straight pipe.

is it a vented loop? has someone tied to install an anti siphon loop at that point ?

The antisiphon loop with this engine would normally be in the hose between the pump and the inlet to the perforated pipe in the cylinder head IIRC

The straight tube on the raw water cooled engine can be replaced by one with two elbows that allow hot water to be piped through a calorifier. It is perfectly possible to do this as a DIY job, or you can buy the pipe from Volvo for an unbelievable amount of money. Photos on https://coxengineering.sharepoint.com/Pages/Calorifier.aspx If no calorifier was fitted it would be necessary to connect the two elbows with a short length of hose.

Answering the OP, as others have said, the tube pushes into the fittings at each end using elastomeric O-rings. They never seal again once disturbed, so prepare to replace them.

 

[VicS]

The straight tube on the raw water cooled engine can be replaced by one with two elbows that allow hot water to be piped through a calorifier. It is perfectly possible to do this as a DIY job, or you can buy the pipe from Volvo for an unbelievable amount of money. Photos on https://coxengineering.sharepoint.com/Pages/Calorifier.aspx If no calorifier was fitted it would be necessary to connect the two elbows with a short length of hose.

Answering the OP, as others have said, the tube pushes into the fittings at each end using elastomeric O-rings. They never seal again once disturbed, so prepare to replace them.

 

[Len Ingalls]

I was looking at some photos of a 2002 for sale on ebay and the pipe from the thermostat housing to the elbow was straight. Flying visit to the boat yeaterday evening to collect a few things - noticed this pipe on mine has a "u bend" with a removeable section connected by short hoses and jubilee clips?

BTW there is a nut on the side of the thermostat housing - what is this for?

Perhaps yours is eqp'd for an optional calorifier. The tube from t-stat to exh ell is "broken" as shown in this link. The 'broken" section can be bridged by a short loop of hose,if calorifier was removed. https://www.dropbox.com/s/ei0ui9tp6fgpkxl/VP 2003 Cooling & Ext Heater Sys.pdf?dl=0

 

[eddystone]

Perhaps yours is eqp'd for an optional calorifier. The tube from t-stat to exh ell is "broken" as shown in this link. The 'broken" section can be bridged by a short loop of hose,if calorifier was removed. https://www.dropbox.com/s/ei0ui9tp6fgpkxl/VP 2003 Cooling & Ext Heater Sys.pdf?dl=0

Yes that looks like most likely explanation; either one of two previous owners decided to fit calorifier and then changed their mind or maybe the pipe needed replacing and engineer only had one with the calorifier take off - it's been bridged with a couple of sections of hose and a metal section.