Possible starter issue

[gw33gp]

When I start my 4.0 SOHC engine, I get a little rattle after it starts that sounds like it is coming from the starter. It is very brief and doesn't sound serious. It seems like the starter gear is slow to disengage or is rattling a little as it slows down.

Has anyone come across this issue? It has been doing it for about a month and is not getting any worse. Should I be concerned and rush out to get a new one? It is the original starter with over 295K miles on it.

Normally, I would just replace it, but I don't think I can get it out without removing the transmission. Even then I don't think it will be easy to get out. It is in a tight area.

 

[Uncle Gump]

The starter comes out... pretty tight working above the front diff.

You certain the noise is starter? Those timing chain tensioners if weak will sound like a 2 second drum roll on a snare drum on a cold start until oil pressure pumps them up.

 

[Uncle Gump]

A simple test to rule out a chain tensioner...

Pull the fuel pump relay on a cold start.

Crank engine a couple times to ensure oil has made its way up to pressurize the tensioners.

Plug fuel pump relay back in.

Start normally.

If rattle goes away upon start up... weak chain tensioner.

Still rattling... likely to be elsewhere.

 

[Broosedamoose]

You could also push the accelerator to the floor before cranking which will turn off the injectors instead of pulling the fuse.

 

[gw33gp]

I have been trying the start with building the oil pressure by cranking the engine with the pedal to the floor before trying to start. What I find is; sometimes I get the light rattle and sometimes I don't. I get the same thing if I just try to start without building oil pressure first. So, I got mixed results. I am still leaning toward the starter as the problem, especially since the tensioners were replaced less than 50K miles ago.

One thing I noticed was how long it takes for the oil pressure to build up when cranking with the accelerator pedal to the floor. I have to crank longer than I like to get oil pressure. When I start and the engine fires right away the oil pressure builds almost instantly. I guess that higher rpm after start makes a big difference.

 

[gw33gp]

This is an update on the rattle I was getting sometimes.

I finally got around to replacing the starter. It was starting to turn over slower and it had over 300K miles on it so it needed to be replaced anyway. It totally solved the rattle problem and spins over like it should now.

I had to remove the transmission to replace the slave cylinder so it was perfect timing for the starter replacement.

So this is something to consider for anyone that is getting a slight rattle at startup as an alternative cause instead of the cam timing chain.