Last post on Sep 23, 2013 at 3:55 PM
You are in the Dodge Dakota-2010 and older
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Dodge Dakota, Truck
#77 of 261 Re: Dodge Dakota 2002 Overheating [bpeebles]
Sep 20, 2007 (8:10 pm)
I wanted to let you know that through your advice my truck is now back on the road. I did the burp thing as you advised, put an identical thermostat in truck to the one I took out, and all is well with my Dakota. Sir, I appreciate all the advice/help you gave in getting my truck fixed. THANK YOU SO VERY MUCH. I do have one more question. Why is the 4.7L called a semi hemi?
#78 of 261 Why is the 4.7L called a semi hemi? [tommy63]
Sep 21, 2007 (5:06 pm)
That is an easy to answer question...
First of all, lets review why an engine would be called a "Hemi" in the first place. The term "Hemi" is slang for "Hemisperical". In a piston engine, the area from the top of the piston to the top of the cylinder head by the valve heads is known as the combustion chamber (this is actually just an area of air!). The combustion chamber on most overhead valved AUTOMOTIVE engines are either wedge shaped (think of a piece of pie) or hemispherical (think of tennis ball cut in half). The cylinder head design dictates the combustion area shape, so when someone says "hemi", it really only refers to the engine's cylinder head having a hemispherically shaped combustion chamber.
Hemi heads have the spark plug located at dead center of the combustion chamber, which makes for an extremely efficient & powerful fuel/air mixing & flame burn (actual igniting of the fuel/air). Hemi heads also have ideal valve placement to help the flow of air (intake & exhaust) through the cylinder head. In simple terms, the head design is VERY efficient, and allows an engine to make excellent power! On the downside, hemi heads themselves usually are quite heavy & large, and valvetrains can be somewhat complex (read: expensive).
The 4.7L engine is a "semi Hemi" because the head is almost a perfect sphere... except for a small bump.
Here are some links which further describe the 4.7L semi-hemi
#79 of 261 Re: Why is the 4.7L called a semi hemi? [bpeebles]
Sep 22, 2007 (8:23 pm)
Thanx for the explanation on the engine. My wife said to tell you Thanx very much for the help in getting our truck fixed. Again, Thank You.
#80 of 261 Re: Why is the 4.7L called a semi hemi? [tommy63]
Sep 24, 2007 (2:51 pm)
As an aside to Bpeebles excellent explanation, when Chrysler first developed the "semi-hemi" combustion chamber in the 1950s, they were referred to as polyspherical engines, meaning they used a combination of wedge and hemispherical designs.
#81 of 261 blower motor switch
Dec 07, 2007 (7:33 pm)
94 dakota 318 w/air 2wd
short story... blower motor worked only on high. then it didn't work at all. the way it happened i'm pretty sure it is the speed control. checked resistance on it but without documentation for the terminals....
help me please!!!!
#82 of 261 Re: blower motor switch [magnummark]
Dec 08, 2007 (5:29 pm)
It's your fuse relays. My blower wouldn't even work. Mine was on the outside firewall in the engine compartment on the passenger side.
I hope that helps.
#83 of 261 Re: blower motor switch [magnummark]
Dec 08, 2007 (7:55 pm)
Check the Blower resistor - that is the most common failure for blower motor issues. It is the resistor which determines all the fanspeeds.
#84 of 261 Re: 01 Dakota Fan speed help. [bpeebles]
Dec 12, 2007 (10:40 pm)
HI- I have a '94 dakota and had the same problem had the heater/ defrost on and it just stopped blowing. Have searched the archives and did as suggested. Replaced the resister (only $7). Didn't fix the problem, so then I pulled out and tested the blower motor. Tested fine as well (but Hubby replaced it anyway ($60)). But at last it still will not work. Any other suggestions. It is so cold we need it daily.
#85 of 261 Re: 01 Dakota Fan speed help. [nanell]
Dec 13, 2007 (5:27 am)
I would be rather shocked that the resistor replacement didn't fix the problem. Try pulling out the resistor and putting it back in a few times to engage the pins. I would also suggest checking the new resistor to make certain that the new part wasn't defective. And, I would suggest describing the complete scenario of what/how much of functionality you have, when and how it stopped working, etc. There are some really savey people on this forum that can trouble shoot based on a very concise description of the problem. And definitely check ALL fuses that could be related (in the regular fuse panel, as well as, the panel in the engine compartment). Good Luck.
#86 of 261 Re: 01 Dakota Fan speed help. [nanell]
Dec 13, 2007 (3:01 pm)
Try wiggling the wires as they go into the connector at the resistor. Do this for all fan speeds. The wires where they crimp onto the terminals in the connector can burn into. It is hard to see this down in the connector. If the blower tries to run when the wires are wiggled you need to install a replacement connector. Be sure to use the largest wires that come with the new connector.