Mitsubishi Repair Questions? Ask a Mechanic for Answers ASAP
Can you describe the noise a bit to me; the sounds as well as when it occurs?
Also, your loss of power... does it seem to take more effort to reach speed, or is reaching speed impossible?
louder exhaust, slightly less power
reaches speed but strains
Just to be clear, there were no issues prior to having the timing belt and air filter changed, these were just done as preventative maintenance?
very quiet, very peppy
Thanks. A couple more clarifications:Do you have a service engine soon light on? How many miles have been driven since the service work?Was anything "tried" or recommended to fix the problem yet?
the problem was immediate after service but now have about 100 miles
the shop ran diagnostics but not sure what exactly
One last question, do you hear any abnormal noises, particularly when accelerating? Perhaps a metallic rattle or clanking sound?
they reverified the timing mark on belt
How about the noises on acceleration, anything abnormal there?
no just sounds like loud exhaust coming from the engine rather than the tail pipe
Thanks, XXXXX XXXXX vehicle present for some quick checks?
Great.As I'm sure you guessed, if the vehicle didn't have a problem on the way in, we are going to be looking at an error in installation of one of the service parts. Having double checked the timing belt is a good thing, though not ruled out yet as an issue for reasons we can get into later if necessary. I'm a bit more concerned with the air filter installation right now due to the noise situation.....
the sound reminds me of removing the air filter and driving it that way
Right, this is exactly where I am going with this as well
What can sometimes happen during air filter installation is that either the hose can be left loose, or less likely to be noticed, the bottom half of the air filter housing can separate from each other
remember that they didnt change filter till after we took it back
WHen this happens, everything looks OK, but the bottom half of each side of the box is really flapping away while you drive
So lets start by going out to the vehicle, and checking our filter installation. There is a large baffle mounted over top of the air filter housing. We will need to remove this first. There will be a metal clamp on either side to pop off, then you can pull the baffle off, or just rotate it out of the way
Once out of the way, reach down and grasp the air filter box on either side, and try to pull them away from each other, lets see if they are locked up tight or if they feel loose
Oh I'm sorry, I got ahead of myself typing there and didn't see that
With the air filter ruled out as a cause, since it was occurring prior to air filter replacement, then we are restricted to only a belt alignment issue
As I mentioned before, just having visually double checked the belt timing does not necessarily mean the belt timing is OK on this vehicle.Was this belt done at a Mitsubishi dealership or independent shop?
checked filter housing anyway. loks good and no hoses left off
independent but they have a real good reputation and past history with us has been good. They said if the belt was off one tooth it would have drastic power loss.
It would be significant, though I have seen vehicles come in with one tooth off and not realize it, just thinking that is how the power level should be. This is not my concern here however.
I changed belt on a 93 2.4 L and there was no timing mark where it was suppose to be one
The engine in this vehicle has a very specific timing setup, and it is possible (in fact extremely likely) for the belt to be installed incorrectly, even though the marks are all lined up. This is something I see on a weekly basis on these vehicles from timing belts done incorrectly... and it isn't matter of the shop not being any good, just a matter of them not being familiar with this particular setup
sounds like your onto something
The problem here is with the oil pump on this engine. The engine has two balance shafts. One is run off it's own timing belt, right behind the main timing belt. No big deal with this one. The other (primary) balance shaft however is run off the oil pump
The oil pump, being... well, an oil pump, consists of two gears meshed together. The balance shaft is run off the second gear of the oil pump, behind the scenes, out of view
Because it is not direct driven off the main belt, there is a gear reduction that occurs on this pulley for the timing belt
When you pull the timing belt off, with everything 'lined up', there is not just one position (where the mark is located) on the oil pump that can be aligned, but rather -six- locations
To make things worse, these six locations occur in three places along the gear.... remember that gear reduction? That means the gear turns six times, across a 2x reduction to align with the cam gear.... so in a nutshell.... you can have the marks all lined up perfect, but your oil pump gear is actually a full 360 degrees out of time... or out of phase
I remember this oil pump timing but the engine has no vibration
When this happens, of course everything looks fine, but when you go to drive, you will have a power reduction as the two shafts fight each other. In single shaft applications you just had a vibration, but now you have them working against each other which results in poor power quality and a lot of noise
This is the first thing we would need to check is the phasing of the oil pump
Beyond this, the only things that could even remotely affect the vehicle in the way you describe... based on -only- the timing belt being changed, would be belt over-tension... but that would be more of a noise issue than a power problem
How will I get the correct timing on the oil pump.
There simply isn't anything else that could be done during a timing belt that would affect either noise or power delivery... the belt tension and phasing aside..... well you have acrank sensor that gets unplugged... if it were damaged/unplugged/etc the engine wouldn't run. Everything else is non=performance related
There are two ways you can check the phase of the oil pump... neither is a lot of fun....
The first, by the book method, is to use the alignment guide hole in the side of the block
To do this, you will need to first set the engine to TDC (align cam pulley), then locate the alignment guide hole. The guide hole is on the left (radiator) side of the engine, about 3" above the oil pan seam, and about 5 inches back from the front cover. It is easy to identify, as it is the only 14mm bolt that doesn't hold anything on... it is just a bolt threaded intot he block
Remove the bolt, and take a screwdriver or allen wrench, etc that is about 3" long and insert it into the block. This is not a lot of fun as the exhaust makes it difficult to just 'grab a screwdriver', as too long and it won't fit.If the screwdriver/allen wrench/etc can not go at least 3" into the block, the oil pump is out of phase and needs to be spun one full turn. If the screwdriver slides in and you think it is in all the way, -gently- rotate the engine. You should not be able to spin the engine, it should be locked in place (DO NOT use the starter!)
The second way is much easier but only if the belt is apart. With the timing belt off, rotate the oil pump pulley to the aligned position, then twist is ~45 degrees to the right or left. In either direction, the pulley should 'spring' back into the aligned position. If it does, the pulley is in phase and OK to install the belt. If the pulley is out of phase, gravity will cause it to continue spinning after you let got of it (turn it to 45 degrees and it will continue to rotate to about 100 degrees away from aligned--- this is bad)
reminds me of my errors on the 93. I made the same mistake. Except had terrible vibration. will there be any possible engine damage running the engine this way
No, if the only thing wrong with the belt timing is the oil pump phase, it will have -no- detrimental effect to the engine. In fact I did a timing belt last week on a car that had the pump out of phase for 60k miles since the last belt job. No issues there.
thankyou for your time
Now if the cam is out of time, that is another story.... and again 1 tooth would cause notable but not outrageous power loss... though less of the sound that the balance shaft can make
No problem at all, I hope this is able to correct the situation;
as I mentioned before, if nothing else was done but the timing belt, this and belt tension are the only things that could cause this issue... nothing else that could cause these symptoms would have been touched during the job, so checking phase is step 1