Exhaust in Overspill/ Rough at Start... Head gasket?

X98STSX · #1 (**permalink**) 02-12-05, 12:02 PM

First, let me say what a great job you guys do helping everyone out... My 98 STS Started acting ugly at cold start this week. I lost most of my coolant, and the "CHECK COOLANT" Message appeared. It looks like exhaust is getting into the overspill. the car runs well otherwise, once we're going. Is this the head gasket, or something I can easily fix?

X98STSX · #2 (**permalink**) 02-12-05, 12:16 PM

Also, white exhaust with sweet, gas smell...

91TexasSeville · #3 (**permalink**) 02-12-05, 01:53 PM

X98STSX

Eeeek! Not a good sign, but fixable. Double dose it with cooling system conditioner/sealer and refill with 50/50 DexCool mix only. Cross your fingers!

X98STSX · #4 (**permalink**) 02-12-05, 04:10 PM

Thanks for the reply. I just got back from getting the sealer and was going to do just that! Before i do, is there a specific kind to use? I have rwo different kinds of Bar's... don't wanna use the wrong one. One is brown liquid with pellets in it, and one is the regular stuff...

JP0013 · #5 (**permalink**) 02-12-05, 04:35 PM

I would recommend using only the GM tablets for sealant. You probably can't get them this weekend, but I think it would be advisable to wait. I paid ~$7 for 6 tablets.

X98STSX · #6 (**permalink**) 02-12-05, 06:03 PM

You get those at the dealership?

JimD · #7 (**permalink**) 02-12-05, 06:09 PM

Wal-Mart usually has the same material from GM's supplier. Look for item G12BP or HDC on this page:

http://www.barsproducts.com/origin.html

Mark G · #8 (**permalink**) 02-12-05, 11:40 PM

Don't waste your time with the block sealer, just rip those heads off and replace the headgasekts. Or, pay someone to do the job right. This is a Caddy we're talking about here -- and a damn nice one.

I've used block sealer before on a Mustang I paid $25 for years ago. I replaced the head gasket but it didn't fix the problem. The block sealer worked ...for a while. Then about every few months I'd have to add more. Ya had no confidence in it.

You can almost ALWAYS look closely at the head gasket and see where it went bad. Also, the spark plug in that cylinder will look like new compared to the others. That's also a tip-off on where the head gasket went bad.

Good luck,

Mark G

X98STSX · #9 (**permalink**) 02-13-05, 12:05 AM

Thanks guys. I'll get into it and check it out in the morning... I'll let you know... I replentished the coolant and drove it on a 20 mile round trip this evening, and it started fine, ran smoothly, and it looks like the coolant level is the same, but this may be a hot/cold thing. It hasn't given me ANY codes for this. Doesn't the car throw a code if you misfire? Also, my temperature guage needle is ALWAYS EXACTLY in the middle while the car is running. It's cold in the morning and i watch it warm up, but no matter if i stomp it or idle in traffic, it never heats up at all. Should i Check anything out. ok... don't wanna get too distracted from the topic.

Thanks again, everyone!

Ryan

91TexasSeville · #10 (**permalink**) 02-13-05, 05:54 PM

Quote:

Originally Posted by X98STSX

Thanks guys. I'll get into it and check it out in the morning... I'll let you know... I replentished the coolant and drove it on a 20 mile round trip this evening, and it started fine, ran smoothly, and it looks like the coolant level is the same, but this may be a hot/cold thing. It hasn't given me ANY codes for this. Doesn't the car throw a code if you misfire? Also, my temperature guage needle is ALWAYS EXACTLY in the middle while the car is running. It's cold in the morning and i watch it warm up, but no matter if i stomp it or idle in traffic, it never heats up at all. Should i Check anything out. ok... don't wanna get too distracted from the topic.

Thanks again, everyone!

Ryan

bbob wrote that the NorthStar temperature sensor is located in a strategic part of the block near the exhaust manifold. The coolant level must at the sensor level in order for it to read properly. Check the output of the sensor first.

STS 310 · #11 (**permalink**) 02-14-05, 03:35 PM

Quote:

Originally Posted by Mark G

Don't waste your time with the block sealer, just rip those heads off and replace the headgasekts. Or, pay someone to do the job right. This is a Caddy we're talking about here -- and a damn nice one.

I've used block sealer before on a Mustang I paid $25 for years ago. I replaced the head gasket but it didn't fix the problem. The block sealer worked ...for a while. Then about every few months I'd have to add more. Ya had no confidence in it.

You can almost ALWAYS look closely at the head gasket and see where it went bad. Also, the spark plug in that cylinder will look like new compared to the others. That's also a tip-off on where the head gasket went bad.

Good luck,

Mark G

Some people like to get a good idea of what to expect before dropping precious dollars. A $3000+ job is not something everyone can just do at the drop of a hat.

Geez, If we all just torn down our N* because of what could be a minor problem, this form wouldnt be as informative. Give it a while for some more "knowledgable" members to post on this thread.

In other words, dont fret yet!

**Ranger** · #12 (**permalink**) 02-14-05, 08:35 PM

Quote:

Originally Posted by X98STSX

Thanks guys. I'll get into it and check it out in the morning... I'll let you know... I replentished the coolant and drove it on a 20 mile round trip this evening, and it started fine, ran smoothly, and it looks like the coolant level is the same, but this may be a hot/cold thing. It hasn't given me ANY codes for this. Doesn't the car throw a code if you misfire? Also, my temperature guage needle is ALWAYS EXACTLY in the middle while the car is running. It's cold in the morning and i watch it warm up, but no matter if i stomp it or idle in traffic, it never heats up at all. Should i Check anything out. ok... don't wanna get too distracted from the topic.

Thanks again, everyone!

Ryan

Yes it will throw a P0300 code if it detects a misfire but it takes more than just a slight misfire to set it.

If it is a head gasket, and it is a small leak, you may have temporarily pluged it if you added the sealant tabs.

X98STSX · #13 (**permalink**) 02-14-05, 10:24 PM

I added the tabs and it seems to be holding coolant for now, and it's not smoking... Just went to work and back, and didn't have time to check the plugs. Today was the warmest weather we've had in while, and when I stopped, there was either boiling or air pressure bubbling in the surge tank. Only code was IPM U1255 - Class 2 Communication Malfunction (Serial Data Line Malfunction). Only had this car since Nov., so i'm not speaking that language yet! Can someone translate? By the way, the car has 107k on it now (after my 6k+), so it's NOT new(it HAS been maintained VERY well), and I expect a few problems. I just hope i don't have a gasket problem.

**Ranger** · #14 (**permalink**) 02-14-05, 10:57 PM

If it is bubbling in the surge tank, I hate to say it but that is a pretty good sign that a head gasket is gone. Especially with the other symptoms you mentioned earlier. Smell the surge tank. You should be able to smell exhaust gas.

Not real sure about the Class 2 Communication Malfunction. May time that code will trip when battery power is lost. Usually nothing to worry about.

zonie77 · #15 (**permalink**) 02-15-05, 11:48 AM

The usual symptom (besides loosing coolant) is overheating after a hill or WOT blast. Your symptoms sound like a head gasket. If you are fairly mechanical you can do it yourself but it is a long process and the engine does have to come out. The sealant is a bandaid at this point.