What Causes a Diesel Engine to Lose Power?

10 Reasons Why Engines Lose Power Over Time

10 reasons why engines lose power over time.

I’ve organized this into four categories because internal combustion engines and more specifically gasoline internal combustion engines really need four things in order for that smooth combustion to occur you need air. You need fuel, compression and a spark.
And so we’re gonna walk through these different sections and talk about how your engine could start to lose power over time.
Based on these four different parameters not working out so much in your favor so getting things started right off the bat with air filters, this is something super simple to fix.
But you can get air filters that clog up with time as debris gets in there and so this can cause a pumping loss for
your engine.
Your engine has to work harder to bring in air because that filter is clogged up and it may not be able to pull in as much air and so as a result you can’t make as much power.
Number 2# is the throttle cable and this relates to cars with mechanical throttle cables this cable can loosen over time.
It’s a super simple fix to just retighten it.  It can stretch over time and as a result you may not be able to open your throttle all the way and not be able to get in all of that air and therefore you’re gonna be making less power.
Let’s kind of move to the exhaust side.  The air of course has to move through that engine nicely on both sides.
So your catalytic converter can get clogged up over time from rich air/fuel mixtures. You can have
deposit build up in there reducing and restricting air flow through your exhaust causing additional pumping losses.
And you know also these mufflers as they age some of them can even rust and that internal piping can kind of fall apart and as a result, it may not act as efficiently.
 Number #3 is fuel injectors.
And you know as a result of heat soak as a result of using poor fuel these can get clogged up with time from particulates within the combustion chamber.
Of course, it can cause your air fuel ratios to be thrown off and as a result you’re going to be making less power.
Also on the fuel side is the fuel pump and these can wear out over time and so you’ll kind of notice this.
Because on the low end they’ll work just fine.
And they’ll be able to supply fuel and then as you get into those higher rpms with high loads or in you know higher loads for a long duration.
The fuel pump may start to struggle and not be able to meet that fuel demand if you’re going up hills if you’re in that high load.
And you’re struggling to get power it may be a failing fuel pump that can’t quite deliver that fuel quantity anymore
Number #4 is piston rings wearing down, and this is one of those things that’s a bit more challenging.
To replace because it requires stripping down the entire engine to get to those piston rings in order to replace them.
if you were needing to do that basically a whole engine rebuild but these piston rings will wear against the wall over time and over time.
You can have increased blow-by and as a result, you’re getting less Compression.  So one thing you can really do to help prevent your piston rings from wearing.   Just make sure you stay on top of your oil change intervals to make sure that those piston rings.
Number #5 and this one’s going to play a big role in how much power you can create.
And this deposits on your valves and more specifically your intake valves. So over time
you know especially in direct injection engines which don’t have port injection where that fuel is being sprayed over the intake valve and constantly cleaning it off. And you have your positive crankcase ventilation system where you’re sending oil back through your intake and then on to your intake valves.
Or it can start to build up those deposits on it.
So this can cause a lack of Compression because that intake valve may not be able to properly seat in that valve seat and it can also cause Backfiring.  you know as you’re compressing back in you may be able to squeeze some of that air fuel
Past that intake valve and as a result you know you’re not gonna have good compression
You could have backfiring if that
Combustion is able to exit past that valve and of course it also plays a role with your air and fuel as it can cause
Additional restriction for air flow to come by and it can mess with your air fuel ratios
Number nine is spark plugs and these can get fouled up with time from fuel, from oil, from carbon deposits,
And this can cause an inconsistent spark and of course misfiring
So you of course need your spark plugs in good working order in order to make peak power and finally number 10
We’re going to talk about knock so as you start to have these deposits
forming
Within your cylinder walls and on your Pistons these deposits can heat up and cause knock and so if you do start to have knock
In an engine the first thing your engine’s going to want to do is
Retard the timing so fire that spark plug later and as a result if it needs to do that to
compensate and to make sure you don’t have knock you’re going to be losing power because it’s firing that spark plug later
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Dencan Brain
I, Dencan Brain BOŽIDAR, call myself a Torque master. I've always been fascinated with cars and tools accessories. You can call me gearheads or petrolheads. I recently started a blog about welding gear.I am also a DIY welding enthusiast because it is affordable for any household work. Follow me on Facebook, Twitter, Instagram, LinkedIn and tumblr.

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