Cat 3116 slow to spool up

Riptide III

Riptide III

3D
Dec 8, 2007
1,139
Dartmouth MA
Boat Info
1997 Sea Ray 400DA
Cat 3116 TA
1994 Sea Ray Laguna CC 250 Tohatsu
Engines
:
Starboard engine lags behind port from about 1500RPMs until 2000 RPMs. When on a plane,after the port engine has done all the work,. The stbd shoots right up. I did not hear a loud whine from the turbo like the port side.since it had 3400 hours I pulled and inspected it. I replaced the turbo pack and the hot section. Still lags and still doesn't whine like the port. You can hear a slight whine when revved up at idle. Valves where adjusted on both engines 200 hours ago. Could it be fuel timing???? Any suggestions please.
 
No. If you had a Caterpillar tech reset the valves, he should have reset the injector timing at the same time since about 80% of the labor was done in getting to the valves, marking the damper, finding TDC, then buttoning everything back up.
 
fwebster said:
No. If you had a Caterpillar tech reset the valves, he should have reset the injector timing at the same time since about 80% of the labor was done in getting to the valves, marking the damper, finding TDC, then buttoning everything back up.
Click to expand...


Frank, I have the 3116's as well and just had the valves done by a CAT mechanic (he did it as a side job thank goodness!) I asked him about the injector timing and he was of the opinion that my engines sounded just fine and not to mess with the timing unless there was an issue.

My engines turn up just about evenly though with the turbos kicking in around 1800 rpm. Even with 2280 hours on the engines the port engine only needed a slight adjustment. I wish I owned that tool.

Has this been your experience as well?
 
Exactly. Mine are the same. The highest time engines I know of here are 4800 hours in a 370EC used as a charter boat. Turbos begin to spool at about 1500, and are just beginning to add boost at 1800, and are working at 2200.

The reason everyone here has the injectors done when the valves are adjusted is because the Cat dealer and the 2 independents in the area with Cat tooling are very aggressive at charging boat owners. When they hit you with $750/day rental on the truck their mechanic drives to the marina, a $49/per diem charge for meals and "incendentals", $2.50 per mile, 10% of the total bill for shop supplies, you want to make the most of every minute they are on your boat. Caterpillar's unit injection system is supremely simple and exquisitely designed but expensive to build. The overheads are set with a dial indicator and gauge blocks in .001" 's of an inch. If they are off, it effects efficiency and performance, perhaps minutely. If the injectors are grossly out of whack they might cause some turbo lag, but I think you'd see the engine shaking at idle if they were t hay far out.
 
When I got a quote for my 2000 hour service it was almost $10k.

I did all of the work myself except the valves and the injectors and finally found a CAT mechanic who would work for cash.

$400 later my valves were adjusted and new gaskets were on. Benjamin Franklin has a way of motivating folks.


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Frank I don't think he reset the injector timing. I just looked at the receipt and it states, perform Valve adjustment and injector height.
 
The injectors on a 3116 are opened and closed by a cam. Setting the injector height determines the clearance and, therefore, when the injector hits the lobe on the cam and begins to open, how far it opens and when it closes. So, it appears that your complete overhead was reset and the answer to your question is that injector timing isn't the reason your turbo does not spool up. Based on your description, I think you are looking for a problem with your turbo or its control.
 
Are the turbo boots intact and installed completely? Had the same issue with my port side not winding up until up on plane. My local Cat guy came out and found the boot had fallen off.
 
If by turbo boot you mean the silicone boot between the turbo and the inter cooler, I replaced it when I did the turbo and it is secure.
 
Talked to mechanic today. We are going to put on a clear fuel line and check for air. He also mentioned injectors. I'll keep you informed.
 
Boat Guy said:
Curious if you have hand spun the turbos and if you've felt a difference in spin rates between the port and starboard sides.
Click to expand...
Haven't touched or spun port because it works fine. As far as the stbd, I just replaced the turbo pack and hot section. All is fine there. Spins freely.
 
I know it's been a while, but did you ever find the fix for this issue? Mine do the same thing and I just assumed it was normal.
 
If I remember correctly it was the aftercooler. I removed it and took it to a shop to be cleaned.
 
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