3g alt=hotter engine temp

[flashback87]

hey guys, after i installed my 3g my engine temp is a little hotter. it was right about 190ish before i did the swap and now it is between 198-200. would the alternator cause this?

i have an after market temp gauge and i am running a taurus fan on high at all times.

thanks for the help.

 

[HISSIN50]

Did you have the Taurus fan before the 3G swap?

Is there any issue with the belt routing or did the alt pulley diameter change drastically?

 

[f8tlfiveo]

I wouldn't think so... Wonder if the change in pulley size makes the water pump turn slower.. It's only 10 degrees I wouldn't worry about it..

 

[flashback87]

thanks for the replies,

my tarus fan was on before the 3g install and that is when it was running a little cooler. i have always been running under drive pullies and when i did the 3g install the new alt pulley was about the same size as my u/d alt pulley so i did not swap them(i left the 3g alt pulley on)

i did have to go with a shorter belt since the original was squealing like crazy when i did the 3g swap. the new belt is only about .5 an inch smaller and it is routed the same.

any other help or advise would be greatly apreciated.

 

[NIKwoaC]

As long as the WP and crank pulleys stayed the same size, WP speed shouldn't change. Belt length wouldn't cause a change in speed of anything either. The only thing that would change if the alt pulley diameter changed is alt speed, but it sounds like that didn't change either.

 

[flashback87]

any other ideas or is this just normal. i feel like i finally got my car to run at the right temp but ever since the 3g it has been getting hotter but it has been staying right at 200.

 

[HISSIN50]

An alt should not cause the car to run hotter, so it's not normal. Either it's coincidence with warmer ambient temps or something else changed.

 

[90mustangGT]

Mechanical or Electrical temp gauge?

 

[jrichker]

If the secondary power ground (engine to body ground) is bad, the stock electric temp gauge reading will be incorrect. The engine to body ground is also the ground for the electric temp gauge.

The secondary power ground is between the back of the intake manifold and the driver's side firewall. It is often missing or loose. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges.

Any car that has a 3G or high output current alternator needs a 4 gauge ground wire running from the block to the chassis ground where the battery pigtail ground connects. The 3G has a 130 amp capacity, so you wire the power side with 4 gauge wire. It stands to reason that the ground side handles just a much current, so it needs to be 4 gauge too.

The picture shows the common ground point for the battery & extra 3G alternator ground wire as described above in paragraph 2. A screwdriver points to the bolt that is the common ground point.

The battery common ground is a 10 gauge pigtail with the computer ground attached to it.

Picture courtesy timewarped1972

Correct negative battery ground cable.