Garra671

About 3 weeks ago I installed a borla midpipe and overacle exhaust. Since then I've noticed my MPG has dropped by 3-4 (not sure if this is a symptom of just me driving)

when I was on the freeway the other day I noticed that when I downshifted to start doing a small pull my rpm slowed down to a snails pace after 4000 (I was in 4th gear at around 80mph)

the next day i noticed a ticking sound from my engine; it doesn't happen at idle or startup it happens at around 2000 and above. I was thinking it could be a lifter but wouldn't it happen at idle as well? I was also thinking maybe an exhaust leak and everything else has been in my head? I'm not sure what's going on I pulled the valve covers and the springs and rockers appeared to be fine; but I'm going to take another look at them today.

Here is a link to a video my buddy took of the sound.

https://instagram.com/p/BW273mintHF/

buckmeister2

You already know that a correctly-installed midpipe-back will not take mileage down more than a couple tenths, if that. I would first go with my driving style change due to the fun of the new sound and (possible) power. You may also be looking more carefully at things you never noticed before, since you recently did the work, and don't want to screw anything up.

Did you check to make sure there was nothing in the midpipe before install? I have found blockages by styrofoam peanuts, and mice/rat nests. A blockage could seriously hurt performance. Was the axleback brand new? It, too, could be blocked.

Garra671

it was all used used when I bought it but we shook it around enough and banged on it enoug (metaphorically) to get it in that nothing was inside of it. But the sound I'm hearing is my bigger concern

enventr

I have had in one of my cars some years ago a ticking that you would swear it was a lifter. I first started to tighten the exhaust manifold bolts and exhaust system. There was a manifold bolt that must have gotten loose over time. After I tightened the bolt the noise went away. It sounded exactly like a lifter. Check the bolts

Garra671

if it was a lifter the ticking would he continous correct?

Garra671

bump

Bruze

From my ancient shade-tree experience, lifter ticking usually goes away above a fast idle.

CMY SIX

did you tune it? More air in- more air out= TUNE.

Garra671

the thing is though I've only really heard it at 1500-2000 rpm. It's not at idle as far as I've heard. I'm going to pull the valve covers and turn the engine by hand; and possibly start the engine as well once it's dead cold so as not too have hot oil spitting out; If one of the lifters is bad the rocker will show that as well correct?

Garra671

no it's not tuned but I've never heard of tuning for a catback exhaust?

Garra671

bump

enventr

Mine you would swear was a lifter. Drove me crazy and I made an appointment to the dealer but thankfully it was a loose bolt. I almost added STP additive to my oil. I checked every bolt. Good luck

Garra671

i just noticed tonight when I was looking at my engine again.

I ran the driver side with no valve cover and didn't notice any difference in how the rocker arms were moving.

I did however notice a bolt on the passenger side on my exhaust manifold snapped. The bolt is still in there but the head snapped off at some point. You think this could be the cause?

Garra671

bump

Bruze

If a lifter is ticking a bit, I don't think you can't tell by looking at the valve train while it's running. I'm assuming you don't have mouse skeletons, pepperoni, chicken bones, etc. swimming around in your oil pan. In other words, the oil is reasonably fresh . . . ?

Have you ruled out an exhaust leak? Short of buying a stethoscope, take a gigantic screwdriver (or something similar) put the handle to your ear and poke the other end around various spots on the heads and elsewhere on the engine and listen.

Another thing: Start the engine at night when the area is dark, pop the hood and look for high voltage spark leaks in or around the plugs, wires, and coils.

Garra671

i have the stethoscope tool and it sounds like it's coming from the very front cylinder on the driver side I pulled the valve covers and ran the engine and brought it up too 2000 rpm and all lifters were moving correctly. Do you think it's a lifter on its way out? (I just changed the oil yesterday).

Still have the noise and i believe the noise started when i when I got a low oil light about a week or so ago; I'm thinking one of the lifters may have collapsed because of that...