Question about cams - MustangForums.com



GT S197 General Discussion This section is for technical discussions pertaining specifically to the V8 variation of the 2005 and newer Ford Mustang.

Reply
 
 
 
Thread Tools Search this Thread
Old 06-11-2018, 12:30 PM   #1  
BismoFunyuns
Thread Starter
 
Join Date: Mar 2015
Location: KY
Posts: 39
Default Question about cams

I have a 2006 GT with ***** thumpr cams. It's an automatic, with 4.10 gears. My question is, when the car goes from drive/neutral to drive or reverse, once the motor is completely warmed up, it will lose it's lope sound? Like the lope sound will come and go, but it mostly sounds kind of weird. Almost like how a diesel truck sounds when idling. Then the lope will come back, and it just goes back and forth between those sounds.

I've always marked it up to these newer motors just don't work the best with cams. I've been in my friends LS1 car with cams and it would constantly have that lope sound to it.

Any ideas?
BismoFunyuns is offline   Reply With Quote
Old 06-11-2018, 05:44 PM   #2  
BismoFunyuns
Thread Starter
 
Join Date: Mar 2015
Location: KY
Posts: 39
Default


i've added a video so you can see what i'm talking about.. notice how it starts idling strage about 18 seconds into the video after i put it into drive? then it gets the lope back once i put it into neutral?

i've always found this odd.. as the car runs fine and i dont have any engine lights. is this something with all cams on these cars or just the thumprs in general?
BismoFunyuns is offline   Reply With Quote
Old 06-11-2018, 05:46 PM   #3  
BismoFunyuns
Thread Starter
 
Join Date: Mar 2015
Location: KY
Posts: 39
Default

a/c and air is all turned off as you can see. once i put it back into drive the second time, it started loping nicely and then starts that weird idle again. it just goes back and forth between it for some reason. but it constantly idles fine/lopey when in drive and neutral
BismoFunyuns is offline   Reply With Quote
Old 06-12-2018, 04:12 AM   #4  
Dino Dino Bambino
3rd Gear Member
 
Dino Dino Bambino's Avatar
 
Join Date: Oct 2014
Location: Cyprus (EU)
Posts: 669
Default

The idle speed seems to increase slightly when you put the shifter into D, and that tends to reduce the lope. Probably normal. You can adjust the N and D idle speeds with the tuner.
Dino Dino Bambino is offline   Reply With Quote
Old 06-12-2018, 09:29 AM   #5  
BismoFunyuns
Thread Starter
 
Join Date: Mar 2015
Location: KY
Posts: 39
Default

Quote:
Originally Posted by Dino Dino Bambino View Post
The idle speed seems to increase slightly when you put the shifter into D, and that tends to reduce the lope. Probably normal. You can adjust the N and D idle speeds with the tuner.
doesn't it seem odd though that it does still lope in drive then changes to that odd sounding idle?
BismoFunyuns is offline   Reply With Quote
Old 06-12-2018, 09:31 AM   #6  
BismoFunyuns
Thread Starter
 
Join Date: Mar 2015
Location: KY
Posts: 39
Default

Quote:
Originally Posted by Dino Dino Bambino View Post
The idle speed seems to increase slightly when you put the shifter into D, and that tends to reduce the lope. Probably normal. You can adjust the N and D idle speeds with the tuner.
the idle speed in drive is lower than neutral/park. It's currently set to 750. I can't get that noise to go away until I set the speed down to like 500-550. Which is too low because the car acts like its going to die when coming to a stop
BismoFunyuns is offline   Reply With Quote
Old 06-12-2018, 06:45 PM   #7  
08'MustangDude
3rd Gear Member
 
Join Date: Jan 2018
Location: Pennsylvania
Posts: 861
Default

A lot of that has to do with valve overlap with the bigger cam. That is not going to go away
without timing tweaks. It sounds like it's lop sided when it does that..

It could also be that one bank is slightly out of time or a cam phaser is slightly off on one bank.

Changing the idle speed up also speeds up the cam movement, so is passes over the lop-sidedness
quicker and then seems to even out. It just has that not so sweet spot at a certain RPM...
08'MustangDude is offline   Reply With Quote
Old 06-12-2018, 08:09 PM   #8  
BismoFunyuns
Thread Starter
 
Join Date: Mar 2015
Location: KY
Posts: 39
Default

Quote:
Originally Posted by 08'MustangDude View Post
A lot of that has to do with valve overlap with the bigger cam. That is not going to go away
without timing tweaks. It sounds like it's lop sided when it does that..

It could also be that one bank is slightly out of time or a cam phaser is slightly off on one bank.

Changing the idle speed up also speeds up the cam movement, so is passes over the lop-sidedness
quicker and then seems to even out. It just has that not so sweet spot at a certain RPM...
So do you think its just the cam in general or a timing/tune issue? Would you think that something out of time would cause an engine light?
BismoFunyuns is offline   Reply With Quote
Old 06-12-2018, 08:12 PM   #9  
BismoFunyuns
Thread Starter
 
Join Date: Mar 2015
Location: KY
Posts: 39
Default

Quote:
Originally Posted by 08'MustangDude View Post
A lot of that has to do with valve overlap with the bigger cam. That is not going to go away
without timing tweaks. It sounds like it's lop sided when it does that..

It could also be that one bank is slightly out of time or a cam phaser is slightly off on one bank.

Changing the idle speed up also speeds up the cam movement, so is passes over the lop-sidedness
quicker and then seems to even out. It just has that not so sweet spot at a certain RPM...
And you say about the increasing the idle speed, that it has that not so sweet spot.. It seems like anything over 500-550rpm idle speed will cause this issue when the car is in drive. This is literally only an issue when in drive.. if its in neutral/park it doesnt make that sound. No matter the idle speed
BismoFunyuns is offline   Reply With Quote
Old 06-13-2018, 04:08 AM   #10  
Dino Dino Bambino
3rd Gear Member
 
Dino Dino Bambino's Avatar
 
Join Date: Oct 2014
Location: Cyprus (EU)
Posts: 669
Default

The torque converter is spinning when the selector is in D, and the increased engine load could be the reason for the change in sound.
Dino Dino Bambino is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Cams, Cams, Cams, jtb727 4.6L General Discussion 11 12-29-2011 04:58 AM
Cams cams cams! marcosbullock 4.6L General Discussion 12 11-27-2009 06:20 PM
CAMS CAMS CAMS samtoyo 4.6L General Discussion 8 11-12-2008 12:46 AM
CAMS CAMS CAMS SayWhen5.0 5.0L (1979-1995) Mustang 3 10-03-2007 07:57 AM
Cams, cams, and more cams. Souperman 5.0L (1979-1995) Mustang 0 09-12-2007 07:56 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Advertising
Featured Sponsors
Vendor Directory

All times are GMT -5. The time now is 04:38 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.