Steamy exhaust

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My exhaust on a Volvo Penta 2002 (raw water cooled) has recently started putting out a lot more steam / water vapour. I can't swear it is not the cold weather but I've not noticed it in previous winters. Impellor,coolant and oil levels are OK. I have a Vetus water lock in the exhaust system which has a drain. Should this be emptied of water periodically and could water in here be the cause of my problem.
Cheers
Andy
 
Look back on recent post for guy with same problem on Bukh.
First check if overheating.
If engine does this all the time, not just when very hot it is probably a restricted waterflow. Check "external" things like impellor in pump, (possible frost damage in this weather) then thermostat, (take out and put in saucepan and heat up, does it open fully) and any external pipework.
If it's none of these things, on a 2002 it could well be deposits internally that are clogging op the transfer ports to the manifold. Also while you have the thermostat out check the transfer ports there. Its unlikely to be anything to do with your watertrap unless its iced up solid and restricting flow. Dont think its cold enough for that. It HAS been cold enough to ice up your waterpump impellor so check that first.
 
Andy,
do You have a reular output of water? If not, or if it is less than usual (may be at hi revs, say 2.700 RPM or over) does the temp buzzer sound?
It could be a clogged water circuit on the engine head (use acid to remove scaling, see previous posts).
Cheers,
Gianenrico
 
The Volvo 2003 is well known for scaling up in the exhaust mixing elbow where cooling water meets the exhaust. I think the 2002 has the same pattern of elbow with narrow channels for the water. You need to take the elbow off and investigate the channels thoroughly with chemicals or much poking with a bit of wire.

Derek
 
although on a different Volvo engine I had exactly that problem with scaling and deposits in the exhaust elbow restricting the raw water flow into the exhaust. One symptom to look for: Does the water level in the raw water strainer drop down when the engine is switched off?

If it does it indicates backpressure caused by a blockage somewhere. The strainer level should be full and remain there even when switched off. Good news is it's an easy problem to fix!
 
I am sorry that this bit of info is second hand. A friend had this problem last year. He tried everything and had almost convinced himself that he had a head gasket problem. However, discussing this at the bar one evening he was advised to change the cover plate on the impeller pump. The plate wears and reduces the efficency of the pump. He changed the impeller pump cover plate and it cured the problem.
 
If all else fails try looking internally at the exhaust hose; these are sometime lined with a flexible pipe which, particularly if overheated, can semi collapse and restrict flow of water and gasses causing higher temperature and steam; usually this is progressive and you end up with the sensors reporting an overheated engine.
 
Is one cylinder hotter than the other? This can be checked by touch on the rocker cover. If one is significantly hotter this may indicate a head gasket.

Donald
 
A friend had a steamy exhaust on a Volvo 2020 & it was caused by the Raw water pump failing & leaking into the Crankcase. The engine breather was drawing the water vapour from the crankcase into the inlet manifold & out through the engine. When the problem worstened the Oil Level appeared to rise as the excessive water filled the Crankcase.

Martin
 
I had this problem last year albeit with an older VolvoMD7.
I don't know if yours has the same symptoms exactly but mine was steaming for a few seconds then ok for about 30 secs then steaming again. I could hold my hand over the exhaust outlet and feel the temp increasing and decreasing as the engine warmed up, as it came up to temp the steam would start to appear. It turned out to be the exhaust manifold. I took it off (4 bolts and a couple of pipes) and found the waterways completely blocked in the manifold, at the constriction where the head meets the manifold and in the various adjoining waterpipes. A couple of hours had the head off cleaned (screwdriver, bent wire etc) and reffited. It now runs nice and cool.
Good luck.
Paul.
 
I have had a similar problem on my 2020 at low revs which was caused by air being sucked into the raw water system through the strainer thereby preventing the impeller from working efficiently. Cured by simply tightening the screw down lid on the strainer properly.

I know it's a different engine but the principles are the same. Worth checking the basics first.
 
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