Changed PTU fluid & Cleaned CAC now poor MPG

[TX MKS-T]

I recently changed my PTU fluid with Redline 75w140 at 35k. I also removed the TB charge pipe so I could get my shop vac with attached hose inside to get the oil out of the bottom of IC. I manage to remove 10oz of very dark PTU fluid so plan another change soon. As far as the IC oil I used the dip stick method and was surprised how much I had, marked 1/4 full on dip stick.

So after doing the said maintenance my MPG went from 20mpg mixed driving to 17.5mpg with no change in driving chararistics. Also not sure if its just me but I can no longer hear my turbos whistling like I did before so not sure if it was due to blocked air charger causing the turbos to over work

Anyone experience similar results with cooler cleaning ?  Maybe PTU fluid change.

[J-Will]

I would double check for a boost leak

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[SHOdded]

x2 on Boost Leak check.  Any electrical connectors disconnected during the cleanup/R&R?  Did you disconnect the battery, that would prompt a relearn?

[TX MKS-T]

I did a once over and my TB inlet clamp was stripped which added movement in pipe so replaced it with a nice T-Bolt clamp but no change in driving. Not sure if it would help to disconnect battery to re-learn at this point or maybe ill check all pipes because I know how it goes when you tighten one pipe it could cause another to go...

On a side note are these engines typicaly noisy at idle and while acclerating ? 

I owned a 2008 Mazdaspeed 3 and found that DSI motor to be noisy so im assuming its just common.

[SHOdded]

What kind of noise is it making?  If you take the appearance cover off, there should be 2 types of sounds (completely normal):  injectors clicking, and valvetrain "clacking" like a diesel engine.  There might be some boost sounds, but usually (OEM) they are fairly well dampened.

If you are hearing rattling, and only on startup, you may want to make sure you use the OEM Motorcraft oil filter.   If the rattle is prolonged, the VCT solenoids or the timing chain may be worn.

Best to put up a video, if you can.  Host on Photobucket or YouTube or similar site.  Also check the PCM for any codes that might be set (and not necessarily trigger a CEL).

[ZSHO]

TX was curious if you removed the [Noisemaker]by the TB,there is a gasket inside which needs to be seated properly or could be Loose causing a host of issues.BTW any pic's by the TB and beyond and check the condition of that [orange gasket].  Z

[TX MKS-T]

What kind of noise is it making?  If you take the appearance cover off, there should be 2 types of sounds (completely normal):  injectors clicking, and valvetrain "clacking" like a diesel engine.  There might be some boost sounds, but usually (OEM) they are fairly well dampened.

If you are hearing rattling, and only on startup, you may want to make sure you use the OEM Motorcraft oil filter.   If the rattle is prolonged, the VCT solenoids or the timing chain may be worn.

Best to put up a video, if you can.  Host on Photobucket or YouTube or similar site.  Also check the PCM for any codes that might be set (and not necessarily trigger a CEL).

Diesel is exactly what comes to mind as far as noise while idiling but also hear some chatter while accelerating at times. I definately have the cold start rattle but have ordered a few FL500s's and looking at picking up some AMSOIL soon as its good stuff having used their trans fluid in the past. I will get a video up soon.

TX was curious if you removed the [Noisemaker]by the TB,there is a gasket inside which needs to be seated properly or could be Loose causing a host of issues.BTW any pic's by the TB and beyond and check the condition of that [orange gasket].  Z

Noice maker like it doesnt already make enough noise lol. Actually didnt notice anything inside the charge pipe, does the MKS use a noise maker ?   Ill have to look again and snap some pics later today.

[Brucelinc]

No noise maker on an MKS.  Yes, sounding like a diesel is normal.  The high pressure fuel pump makes its share of racket.  Common on DI engines.

[TX MKS-T]

So I changed plugs over to SP534's yesterday and running much better. Old plugs had opened up to .38 and new ones that went in were left at .32. Car has 36k miles so i realize these plugs don't last long in these EB motors !

[SHOdded]

Nice!  Though the gap should have been ok with stock tune ... Were the old plugs SP528s, do you know?  Can you share pics?  SP528s had some problems with the insulators cracking.  TIA.

[TX MKS-T]

Umm just noticed they are plats :/

[ZSHO]

SHOdded is absolutely correct to point that out because the Motorcraft SP-528 were Platinum plugs and later were revised to the current Motorcraft SP-534 which are Iridium plugs.  Z

[SHOdded]

Does look like the MKS was running on the lean side, from the color of the insulator.  Let's see if the 534's hold up better!