So far I have replaced the engine temp sensor,thermostat, checked hoses and radiator replaced surge tank,and verified cooling fans are coming on, replaced waterpump and block tested the engine for combustion gasses. The vehicle runs ok at idle but overheats while driving, return to an idle and it will cool off again. Any suggestions?
Posted by pemayer54 on
my husband did everything that everyone else did that had this overheating problem. It was so weird that my engine cooled at a light and heated up going down the road. I have a north star 4.6 engine and this is natorious for happening. my check engine light also came on and so I had a diagnostics done which told me my #1 injector wasn't firing , car ran like **** as well. After putting in a new water pump and plugs,ect. and realized injector was good a friend told him we could have a blown head gasket. So just to see if this was the problem I went to buy a bottle of glassbeads and the auto parts guy told us to purchase a bottle of BARS STOP LEAK BLOCK SEALER NOT RADIATOR BUT BLOCK SEALER $31.99 . He followed the directions and we waited 24 hrs. before driving it. What ever the problem was has stopped my car runs like brand new and I am loving it again. no over heating no injector problem, runs great.......I hope this helps. I know its probly a temperary fix but its a fix and now we know what the problem was. SASSY
Posted on Mar 19, 2009
99 deville...how do you bleed out air from cooling system?
Posted by Anonymous... on
There is no need to bleed air out of the system as the Northstar is self purging.
If you are having overheating problems the most common overheating problem with the Northstar engine is a blocked purge line. It's job is to purge air out of the cooling system.
There is a small diameter hose coming from near the top of the coolant tank(Not the cap!),this is the purge line.
With the engine idling,pull the purge line from the tank,if there is no coolant flow from this small hose,it is blocked and this will cause overheating.If the hose is clear, check for blockage at the nipple on the tank.
Air locks in the Northstar engine shouldn't be a problem as the system is self purging, given that all hoses are clear.
Posted on Oct 11, 2009
does that dura-seal head gasket repair stuff REALLY work?
Posted by bobthemove... on
I had a blow head gasket on my BMW 6 cyl. and it was blowing white smoke and losing alot of coolant. After doing alot of research I found that all the other brands like blue devil, steel seal, KW and bars all use water-glass. The only company that does NOT USE WATER-GLASS is Dura-Seal. If you have aluminum heads it's very important to use a sealer that can flex with your engine's aluminum heads. The DuraSeal actually stays flexible! So I tried it and it stopped the smoke and overheating. No more coolant loss either. It's been running fine for over a year now. I would reccomend Dura Seal head gasket sealer to everyone... Great product! Also the tech department guys really know what they are talking about...
Posted on Nov 09, 2012
north star belt diagram
Posted by pitbu7701 on
Northstar belt routing diagram.
This diagram should also be on top of your engine somewhere, usually on the plastic cover on the radiator.
Posted on May 13, 2010
timing chain diagram 4.6 northstar engine
Posted by mjmmjm4342... on
my caddy is running hot and i want to replace the head gaskets but i need to know how to set the timing
Posted on Jun 27, 2010
1999 cadillac deville a/c off low refrig error code is showing. Compressor won't take in refrig b/c can't get it to come on.
Posted by Randdolph... on
I had the same problem. The mechanic could not get the compressor to take in new freon. It has to do with the car's memory. You have to reset it by disconnecting the hot wire from the battery which for thirty seconds. This resets the cars internal memory, so it won't remember that it's out of freon. Reconnect it turn on the car and turn on the air the compressor will start.
Posted on Jun 28, 2010
how do i replace a heater core in a 1999 cadillac deville
Posted by effective2... on
Here is detailed solution on how to replace the heater core in the 1999 cadillac deville;
STEP 1 Disconnect the negative battery cable.
STEP 2. Drain and recycle the engine coolant.
STEP 3. Disconnect the heater core hoses using tool J-37097 or an equivalent.
STEP 4. Remove the right side sound insulator and the glove box module.
STEP 5 Remove the programmer shield, if equipped, and disconnect the air mix valve link.
STEP 6 Disconnect the programmer vacuum and electrical connectors.
STEP 7 Remove the heater core cover, leaving the programmer attached.
STEP 8 Remove the heater core retaining screws and the heater core.
have a nice day..
Posted on Aug 27, 2010
where is the fuse box to a cadillac deville 1999 located at...
Posted by mykhol... on
One is in the trunk on the driver side be hind the rear seat. Second is under the hood on the driver side by the air filter..
Posted on Jul 08, 2010
Posted by garlandpet... on
Trouble Code: P1258 (4.6L V8 VIN 9 Auto)
Engine Metal Over-Temperature Protection
Number of Trips to Set Code: 1
OBD II Monitor Type: CCM Details
Indicators: MIL Details
DTC P0117, P0118 and P0125 not set, Engine started; and the PCM detected the ECT sensor indicated more than 270ºF for 10 seconds. The PCM uses the ECT sensor to detect if the engine is running too hot (when the ECT sensor is over 268ºF). If the engine is overheated, DTC P1258 will set. The PCM will disable 2 groups of four cylinders by turning off the fuel injectors. By switching between the two groups of cylinders, the PCM is able to reduce the temperature of the coolant and lower the temperature.
Posted on Aug 13, 2010
The dash vents are open and cold air comes out the defroster and floor and rear vents but very little comes from the dash vents.
Posted by josephkwia... on
Check for vacuum hose leak.
Posted on Jun 17, 2009
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