what's dohc or sohc
thanks
Senior Member
Joined: Jul 2004
Posts: 6,200
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From: Easton, Pa.
Since there are valves to be operated on each head, SOHC and
DOHC means one or two cams each side. (single/double). Your's is SOHC.
Do you have a CEL lite on? Is there any codes stored?
If the plugs have not been changed, it's time.
Do cleaning of the EGR passages.
May need new OX sensors.
These are all normal maintaince items that should be changed with the age and mileage of the motor even if there are no running problems..
DOHC means one or two cams each side. (single/double). Your's is SOHC.
Do you have a CEL lite on? Is there any codes stored?
If the plugs have not been changed, it's time.
Do cleaning of the EGR passages.
May need new OX sensors.
These are all normal maintaince items that should be changed with the age and mileage of the motor even if there are no running problems..
Senior Member
Joined: Dec 2004
Posts: 162
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From: OKC
More simply stated, it means Single Over Head Cam (SOHC) or Dual Over Head Cam (DOHC). Goes hand in hand with - 16 valve motor=SOHC and 24 valve motor=DOHC. As far as MSD goes, it is a good brand but I personally would just stick to OEM especially with a stock truck with 100000+ miles. You're not going to notice any performance gain going with an aftermarket performance ignition system more than likely. Make sure you read up on some posts, books, guides, etc. or get a buddy to help before going under the hood and yanking at things...you can screw some stuff up if you aren't too sure with what you are doing. Just make sure you know what things are and where they go. Good Luck 
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Joined: Jun 2005
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From: ALBERTA CANADA
Dohc
Originally Posted by mountnman
I'm looking to tune up my 98 f150 4.6L 4x4 and would like to replace the plugs, wires, os's, coil and whatever else anyone can suggest. It has 104,000 on it now and I purchased it new. I was looking on ebay for some stuff and found msd wires and 4 tower coil for sohc and dohc could you tell me what that is and how to know what I have. Also if msd is a good brand to go with. Or should I stick to oem, and best place to purchase my parts other than the dealership exxxxpppeeennnsssiiivvvee. I searched through the archives and found some good reading just would like to get some more input. The reason for this is the truck started chugging the other night once I got up to 55 ( didn't notice it while it was idleing) so figured it's time for a tune up. All help is Appreciated!!!!!
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Joined: Jan 2005
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From: Fort Worth,Tx
Originally Posted by umachme
IF YOU DONT KNOW THE DIFFERENCE BETWEEN DOHC AND SOHC DONT BOTHER TRYING TO FIX YOUR OWN VEHICLE.....
nicely put :-p
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Joined: Dec 2004
Posts: 5,004
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From: Dover AFB DE / Harrisburg PA
Originally Posted by umachme
IF YOU DONT KNOW THE DIFFERENCE BETWEEN DOHC AND SOHC DONT BOTHER TRYING TO FIX YOUR OWN VEHICLE.....
What kind of bad attitude is that??? Not cool.
Why did the origional post get edited?