Head gasket blown? Bbob one sec of help please...

[SplitSlim]

Hi,

I just returned from the dealership for a full diagnosis and injector flush. My 93 STS N* was idling a little rough, and stalling at times during idle. While at the shop, the mechanic saw a small puddle of oil on the power steering pump side, underneath where the head connects to the block. He is now telling me that the gasket needs to be replaced.

Here is my question. My car does not overheat, the highest the temp has ever been is 106. I am wrong in thinking if the head gasket was blown, the leak would be coolant and not a puddle of oil, the size of a couple of quarters? The oil level is constant, and does not seem to fall drastically. From this information do you think I need to replace my head gasket? He did not do a compression test (funny thing is, before seeing the puddle he said he did not have to, he could "see and feel" that the compression was fine).

Any help would be greatly appreciated

Thanks,

SS

[Ranger]

I would not authorize a repair that expensive on that kind of diagnosis.

[SplitSlim]

That is what I am thinking. I asked him if it was possibly a small puddle of powersteering fluid, he said no, from experience he KNEW it was a head gasket issue. But I could plainly see, if you spilled ps fluid, that's exactly where it would fall.

What can I do to test for a head gasket problem my self? What are the signs/symptoms?

[chazglenn3]

Personally, I don't see how you can have a blown head gasket and never have the car overheat. The exhaust gas entering the coolant would surely make the car overheat eventually. I have a blown head gasket on my 87 Supra right now. There is no coolant in the oil, nor oil in the coolant but the car overheats after driving about 45 minutes.

[SplitSlim]

I've only had the car eight days, however my longest drive to date was over an hour (highway and city)....I'm averaging around 95 degrees celsius.

[Poobah]

It isn't likely that a couple of drops of oil on the floor is a result of a blown head gasket. Are you sure he wasn't refering to some other gasket? Head gasket problems usually result in severe overheating. When that happens you'll know it! The DIC will tell you the car is overheated and to turn the engine off. It will then go into limp-home mode. If you haven't experienced that kind of excitement, your head gaskets are probably fine.

[SplitSlim]

Poobah, the oil puddle was not on the floor, but inbetween the heads. It's hard to explain, but picture looking at the left side of the engine, above the power steering pump, straight down. There is a very small puddle of dark liquid (oil?).

As I said, I have had no overheating problems whatsoever. This is beginning to stress me out immensley.

Should I test but seeing if there are bubbles in the coolant (unscrew the coolant cap and run the motor)?

[Ranger]

Sounds like you are talking about the valley. Maybe this post will help shed some light on it.

http://caddyinfo.ipbhost.com/index.php?sho...&hl=valley&st=0

[adallak]

Can you determine the origine/nature of the fluid? Is it oil, PS fluide, coolant etc. Just wipe it up with a paper towel and compare to one sucked up with oil from dipstick and PS cap.

From what the mechanic told to you looks like he must have some head gasket problem.

[SplitSlim]

Ranger, yes, that's where the puddle is, however not that large. It's on the left side, top corner.

I'll check now what the nature of the fluid is.

Thanks

[SplitSlim]

Well i checked the fluid, it's either oil or ps fluid. Tough to tell, but I'd bet on ps fluid (although I might be wrong).

I saw no bubbles in the coolant tank while running the car, however i saw a little white exhaust, not overly white, but whiter then gray, leaving the mufflers (rising up to about the top of the bumper). You really had to sit there and look to see it.

[adallak]

Well i checked the fluid, it's either oil or ps fluid. Tough to tell, but I'd bet on ps fluid (although I might be wrong).

Are you sure it is not coolant? Supplements make even green coolant look rusty.

[SplitSlim]

Guru, your comments make sense, but I guess I'm used to the reliability of imports compared to this domestic. The car is great, don't get me wrong, but leaky head gaskets at 180,000kms blows my mind. The Lexus I traded in for this car had 280,000 kms on it, and ran like a dream, I was just looking for a change of scenary (not to mention it needed new shocks, ps pump, but the engine was solid as a rock).

I've driven BMWs, MB's and Lexus', now I can add Cadillac to that list, but my initial experiences are not positive. I agree with you that it is a USED car, and that it will have it's problems, and I'm ready to invest in things like ps pumps, suspension, ac retrofitting, etc, but a core component like a head gasket failing is beyond the amount of work I want to invest into this car.

I'm going back to the dealer tomorrow (where I bought the car) to see what my options are. If I can get this rough idle cleared up, I might be able to forget about the "tiny bit of oil in the valley".

Thank you for your assistance, and for the realistic comments. I honestly appreciate any help anyone can offer.

SS

[Regis]

Sounds to me (and to others I'm sure) that the only issue(s) that shoud be addressed at this time are 1) the rough idle and 2) gaining more knowledge and becoming familiar with your 93 Northstar. Most anyone in here will tell you how amazing the engine is..... and how complicated too. Definitely requires more knowledge then that of a 2 stroke outboard .

I had to erase the rant I was originally going to post because it was going in the wrong direction and definitely not productive. However, I would like to point out one thing. When you owned the lexus, I'm betting that you became quite knowledgeable about it and it's workings... yes? You said that it was reliable and solid as a rock, but needed ps pump and shocks. In other words it didn't behave like a new car when you traded it in. I doubt that the dealer will fix too much before trying to resell it. Now you are the new buyer of someone elses old car. See the pattern here? Bbobynski is the expert and authority on the Northstar engine. He pretty much gave your caddy his blessings and gave you some good advice.

Getting back on track. Let's try to fix that rough idle. First you need to learn to access the DIC (driver information center) and the codes (if any). The codes will tell you what is ailing the engine.... and/or the rest of the caddy for that matter.

To enter diagnostic mode:

Turn ignition "ON."

Depress the "OFF" and "WARMER" buttons on the Climate Control Center (CCC) simultaneously and hold until the segment check appears on the Instrument Panel Cluster (IPC

Copy down any codes that are current and post them here so we can help you or you can look the codes up at the link below. The link is also where I got the directions for accessing the codes.

http://myweb.accessus.net/~090/dtcobd1.html

Good luck and welcome to the board!

-kg

[SplitSlim]

kger2, Thanks for the reply.

You are right on by assuming I new my Lex inside and out. With time I will gain that knowledge with this car also. I was stressed out yesterday beyond belief, and a blown head gasket didn't help matters:-)

Anyways, here's an update. I took the car into the dealer where I purchased it, and they are looking at it now. He says that it "might" be the head gasket (covered by warranty, thank god), or possibly the intake manifold gasket, or ps fluid (which I higlhy doubt now after swabbing some of the fluid out of the valley with a paper towl and screwdriver, I'm 90% sure it's oil.) Also, it's not a small puddle as I first thought. The small puddle is on the rear side of the valley, the large puddle is on the front of the valley. We'll see what he diagnosis the problem is later this afternoon.

Back to the rough idling/stalling. I did a lot of reading on this and another board about the DIC. The only code that I had was PO95 - Engine stall detected. No other historical or current codes. I also played around with the PCM Overide for the fuel injectors. I found that injector 1, when shut off, did not make much difference in the "feel" of the engine/rpm. I showed this to the dealer, and he will take a closer look at my injectors. I also replaced the spark plugs with Bosch Platinum +2 (which I now may replace with AC Delco Platinums), checked each spark plug wire for resistance (checked out fine), changed the PCV valve, cleaned the throttle body. I am yet to remove and clean the EGR, replace the fuel filter, or check the FPR (where is the vacuum hose that I need to remove on the FRP to see if the inlet leaks? bottom, side?)

On a positive note however, I successfully installed my aftermarket keyless entry system, alpline headunit, phoenix gold 4 channel amp, alpine 6x9's and alpine components! Oh, can't forget the silverstar halogens and alpine ipod adapter. Running 2 gauge power cable through that firewall and car was fun

I'll write back when I know more. Please don't take my comments in a negative fashion, I would be lost without these forums and without expertise such as Guru's and other's.

Beer's on me once my car's fixed

Thanks

SS

[SplitSlim]

Guru, I replaced the timing belt myself at 160,000kms(originally changed at 80K)...and they don't bend anything in the motor when they snap, as the 4.0l V8 is non intrusive.

The biggest problem in the Lexus LS400 is the powersteering pump leaking on top of the alternator. Major design flaw, but fixed with an inexpensive gasket and custom drip shield.

I'm glad to hear that I won't have to change the STS' timing chain anytime soon;-)

[Scotty]

I am glad your head gasket would be covered under warranty, but dont assume that the dealer will do the repair right, be sure that they Time-Sert the engine, otherwise it will go again when you are outside the warranty period.....

[SplitSlim]

Good point Scotty, I'll be sure to "remind" him.

Thanks

[SplitSlim]

UPDATE!

Good news. My intake manifold gasket was leaking a fuel/oil combination. The dealer had the valley visibile, and the intake off. You could clearly see that gunk was built up in the intake channels and this caused the gaskets to fail and leak slightly into the left half of the valley. Upon closer inspection of the headgaskets, they look flawless. This, I guess, would also explain my rough idling.

The dealer will clean the intake channels, replace the gaskets and off I go. Thanks again for your advice and suggestions.

Relieved,

SS

[Ed Hall]

Guru, I replaced the timing belt myself at 160,000kms(originally changed at 80K)...and they don't bend anything in the motor when they snap, as the 4.0l V8 is non intrusive.

http://www.skillcentre.com/lexus.html

LEXUS

Engine Interference Recommended Interval

2.5L NO 60,000 Miles

3.0L V6 NO (52)

3.0L Inline 6 (1992-97) NO (26)

3.0L Inline 6 VVT-i (1998-01) YES (26)

4.0L YES (26)

4.3L YES (26)

4.7L YES 90,000 Miles

Notes:

VVT-i (Variable Valve Timing with Intelligence).

(26) On 1995 & prior models, replace at 60,000 mile intervals. On 1996 & later models replace every 90,000 miles or 72 months under normal service, or every 60,000 miles in severe service.

(52) On 1990-95 models replace every 60,000 miles. On 1996-98 models except E5300 replace every 90,000 miles or 72 months under normal service, or every 60,000 miles in severe service. On 1996 & later ES300 replace every 90,000 miles or 72 months. On 1999 & later RX3OO replace every 90,000 miles if vehicle operates under severe conditions such as low speed driving for extended ranges, door-to-door deliveries, taxi or law enforcement situations.

[SplitSlim]

Guru,

Do you think this was causing my rough idle, and a component of the stalling I was experiencing?

SS

[jschunke]

Ask the Lexus community whether their 400 v8

is interference or not, and get as many different

answers as there are owners. Kudos to Cadiilac

for designing a durable timing chain. It's a far

cry from those insane nylon timing gears of

time past.