Slow cranking only when hot.

[rubino]

My Volvo 2003 starts 100% when cold. Slow cranking 30% of the times after warm up.Does exist voltage drop only with hot engine ? The connections look good . The starter motor does not have a negative wire its chassis act as negative ( I am planning to add a negative wire) .
It is five years that I endure this bother .
Thanks..please help.

[GRIT]

It's likely your starter windings. Try having your starter rebuilt.

Cheers.
Paul.

[jamhass]

When you say slow cranking, do you mean slow starter rpm or it takes longer to start?

On our 2003t, cold start using the cold start procedure starts immediately. Warm engine starts without the cold start procedure takes longer. With the procedure, starts quickly.

[DeepFrz]

Clean and tighten all connections between your starter and the start battery, including ground cable connections before you do anything else. Its possible that your starter needs servicing but do the simple things first.

[rubino]

Thus I will : 1st) re-clean and re-tighten all connections , 2nd) add a -wire from the starter chassis to the engine block (a logic = hot engine and its contact with the starter chassis ),3rd) give a try with a new starter+solenoid.
Thank you all.

[Kita]

Originally Posted by rubino

Thus I will : 1st) re-clean and re-tighten all connections , 2nd) add a -wire from the starter chassis to the engine block (a logic = hot engine and its contact with the starter chassis ),3rd) give a try with a new starter+solenoid.
Thank you all.

I think there was a misunderstanding, starter as you said is grounded to engine, I think they mean ground from engine & starter to battery ground or neg side of battery & it needs to be a battery cable with good connection as in not on paint on the engine ...

[skipmac]

Originally Posted by DeepFrz

Clean and tighten all connections between your starter and the start battery, including ground cable connections before you do anything else. Its possible that your starter needs servicing but do the simple things first.

Always try the easy, simple cheap fix first just in case. If cleaning and tightening ALL the connections (don't forget to check the battery ends as well) then very possibly the starter needs work. Happened to me on a previous boat. Started fine cold but hot the starter couldn't turn over the engine. Rebuilt starter, problem solved.

[Kita]

Originally Posted by skipmac

Always try the easy, simple cheap fix first just in case. If cleaning and tightening ALL the connections (don't forget to check the battery ends as well) then very possibly the starter needs work. Happened to me on a previous boat. Started fine cold but hot the starter couldn't turn over the engine. Rebuilt starter, problem solved.

Spot on!

[skipper53]

If the engine is turning over more slowly when warm, I would suspect an engine wear problem......Hot engine internal parts -- rod bearings, crank bearings etc., might be creating more friction than when the engine is cold.

[Cadence]

Look at the bright side. Is it possible you are experiencing better compression when hot. You said, I believe, no starter ground wire which is normal. Check the neg. lead to your block.

[Aaarrgh]

Engine timing needs to be checked.

[Vortec]

Originally Posted by Cadence

Look at the bright side. Is it possible you are experiencing better compression when hot...

I agree with Cadence. Last year I rebuild a VP D1 20B and it starts slightly easier cold than warm. It's a question of 1 crank cold and mayby 1 1/2 rev hot. ⛵

[Siberian Sea]

Very good chance the starter is worn out. When it's cold the motor contacts are close but once it's hot the gap becomes larger and the starter looses power.

[a64pilot]

Originally Posted by skipper53

If the engine is turning over more slowly when warm, I would suspect an engine wear problem......Hot engine internal parts -- rod bearings, crank bearings etc., might be creating more friction than when the engine is cold.

Could be I guess, but with about 40 years as a mechanic I have never seen it

Originally Posted by Aaarrgh

Engine timing needs to be checked.

Now this could well be it if nothing else fixes it, too advanced timing will certainly make one spin slower during starting.

[Cadence]

Could be I guess, but with about 40 years as a mechanic I have never seen it

I would have to agree with that. An engine with wear may take longer to start but not turn slower but faster in order to achieve compression.