88 vette - l98 - temp issue
Thread Starter
Instructor
Joined: Mar 2010
Posts: 189
Likes: 0
From: DFW texas
ok well maybe found out my problem
well i ran the engine a hour today and used a scan , my dash temp says 225 and the scanner say 205 so theres for some reason a 15 to 20 degree difference between what the dash says on my 88 l98 and what the computer says , but why ?
as for the high temps im getting i found that my intake manifold is seeping in the front above the water pump , so could that be causing my hight temps
even on the scanner it got up to almost 230 today
as for the high temps im getting i found that my intake manifold is seeping in the front above the water pump , so could that be causing my hight temps
even on the scanner it got up to almost 230 today
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Display is from a Sender (which is a thermistor - resistance decreases the hotter it gets so the voltage drop at the Display is proportional to temp) in the right head between 6 & 8. Coolant Temp Sensor is below the throttle body and that's what the ECM uses to determine fueling (and is what the Scan showed). Quick check of the Display is to disconnect it at the sender. Open - max resistance or no voltage drop - should read Cool or Cold. Grounding the wire - no resistance or 0 volts at the display - should read 300. Check the signal - 12 volts. Make sure the wire is in good shape as it may have been damaged when you swapped out the heads. You might also try a new Sender. Just be sure you tell them you want the Display Sender as 9 out of 10 times, they will pull up the Coolant Temp Sensor. You might just take the old one with you so they can match it up - it's fairly universal across all GM's that have any sort of temp display. A couple of degrees between the 2 readouts is considered normal.
