http://myweb.accessus.net/~090/dtcobd2p.html#pow. This is a good link for codes. Generally codes are identified as HISTORY or CURRENT. I would suspect that the B, body, codes are old and the P1527 is probably old too, it is a nusiance code imo, it senses where the transmission is and where the gear selector says it is, it is easy to get an error here. I don't think P0603 has anything to do with overheating so that leaves the P0300 misfire which would be common in an overheating engineand the other two which are overheating related.

In an overheating engine it is common for coolant to overflow or appear full so have you checked it when it was cold?

If it is full then it would seem likeyou are not circulating the coolant through the engine. This would point to Water Pump or Thermostat or both. There could also be a blockage in the system if incorrect coolant was used in the past or it is really old it gets sludgey. You say no coolant in the oil and no white smoke. I hope you are right.

Get the car to a good shop.

 

Go check out Blown Head Gasket thread under Sevilles. There is a product link there that looks like it fixes the head gasket problem.

 

Well, I changed the water pump just to see if that was the cause and it appeared to be going out. The weird noise my car made while cold is gone so I fixed something. Not sure it has fixed the coolant problem or not so we will see. If not I may try the product from that link under Seville. Thanks for pointing me in that direction.

Sandi

 

Just curious on the water pump job cost. Mine was done under warranty so I never really knew the cost. It's a tiny thing compared to say a Chevy small block pump. Because it is a Northstar the first thing most folks think of when it overheats is head gaskets but a bad pump or thermostat will overheat the engine too. Often overlooked and not really that expensive to repair. I hope you changed the thermostat too. Anyway we all have our fingers crossed for you. Let us know if that was the fix.

 

I changed the pump myself and the pump was only $46.00 but you have to have a special tool to get the pump off and it was right at $30.00. Very easy to do (coming from a females point of view...lol). I checked my coolant level after driving around alot yesterday and there was plenty in the res. Normally it would have been empty. So hopefully I have fixed my problem. I also reset my codes after I changed the pump and my service engine light has gone out.

 

Sounds fantastic Sandi. I think your problem is solved. I'd still be inclined to get some Barr's stop leak. It was common service protocol to put sealer in the Northstars in the past although I undersatnd that now there is a difference of opinion on this, I'd still do it. If your problem is fixed I am going to gloat a while for sending you to the water pump...and to think, I'm an Accountant!

 

Hey Sandi, It's Saturday, Feb, 24th, hows your coolant level? any new error codes?

All this coolant talk so I checked my vehicles this morning too. Deville is good but the darn Suburban had an empty overflow, rad was good so I topped up the overflow tank. It's -10 here in Toronto but you can still overheat them in the dead of winter. Usually when your heater is not as warm as it should be is the first hint of a low coolant condition.

 

I had a check coolant level display this morning. But....this is the longest I have gone without it popping up. Its almost been a week. My boyfriend said that thecoolant/water thatI put in there after replacingmy water pump mayhave beensucked thru everything that it goes thru and that I just needed to refill the resevior. I hope thats it!! I have no new error codes since I replaced the pump. I was getting the 0300 engine misfire. I am gonna check the plugs and wires when I get a spare minute. And I think I may get some of the bars leak. I know they have several different kinds of liquids and a powder. Which one do you prefer? I have heard that one may be better for Cadillacs than the others.

Thanks,

Sandi

 

But it did not Overheat!! I'd go with the bottle with the pellets in it. You can shake the bottles and hear them. Correct procedure is to put it in the lower radiator neck, but you won't be able to do that with a full system so into the reservoir. How much Coolant did you have to add? Couldn't have been too much. It is possible for the coolant to settleBut....we're keep our fingers crossed.

 

No it didnt overheat. I got to thinking. It gets hotter when im just sitting at a light or something then it cools off while driving. The temp got up to 252 and of course i wanted to start cussing cause I thought I had it all fixed.Once I was driving the temp went down to 206 pretty quick and it normally stays between 196 and 206. I dont think the thermostat opening all the way. I am going to change that after I get off work today. Im also gonna get a new cap and get the pellets. I havent put anymore coolant in yet. I was going to but I thought I would change the thermostat when there is less coolant/water. Ill let ya know.