Slow Coolant Leak, Smoky Starts, And Lifters Ticking

05silvycrew · October 3, 2009

Hi, I've done some research and it seems that these issues are potentially all related to a TSB put out in June of 2007 that I found in THIS thread. my truck is a 2005 crew cab silverado, with 5.3 iron block, z71, about 90,000 miles on it.

Just to go into it a little more detailed, here's what has happened recently. About 3 weeks ago, I jumped in my truck in the morning to go to work. It was one of the first colder morning so I turned the heat on and waited...and waited....and waited. the engine reached full operating temperature, but I didn't get any heat out of the vents. When I returned home from work, I opened the hood to take a quick look around and noticed that my coolant resevoir was nearly a gallon low. rushed over to Autozone and got some GM approved (had the official GM symbol) Prestone Dex-coolant. topped off the resevoir tank and took it for a drive and the heat came back on. gave it 2 days and checked it again, it was about 1/2 gallon low. I just figured that some of it had worked its way back through the system. So I again topped it off with the same coolant. Drove it and constantly checked it for the next week, and the system held just fine.

That is until last weekend, on my way to work one morning and again the heat would not come on. Get home from work and the coolant is about 1/2-3/4 gallon low. So, now I'm looking around, under, and inside everything and can't find a single drop of this stuff. I'm pretty sure I can smell it when I open the hood after the engine has been run at full temp for a while, but can't find it anywhere.

Next morning (Saturday) I go to start my truck up and a big puff of blue/white smoke pours out of the exhuast pipe. That's never happened before so now I'm freaking out and have all my senses tuned for the slightest hiccup in the engine or any sign of something being wrong. I can't hear anything or see anything or feel anything out of the ordinary. Since then (a week ago) the exhaust will smoke a little upon startup, but never like it did that day.

Flash forward to yesterday morning. I get in the truck, again it's cold out and turn it over and I get this loud ticking/clicking sound out of the engine. It's in sync with the RPMs (faster or slower as I speed up or slow down) and sounds like a baseball card in the spokes of a bicycle. after the engine warms up though, the ticking goes away and is not audible.

The TSB I refered to earlier looks like this:

Document ID# 1986750

Subject:Information on Gradual Coolant Loss Over Time with No Evidence of Leak Found #06-06-01-019B - (06/12/2007)

Models:2004-2006 Buick Rainier

2001-2006 Cadillac Escalade Models

2001-2006 Chevrolet Avalanche, Blazer, Silverado, Suburban, Tahoe, TrailBlazer Models

2001-2006 GMC Envoy, Jimmy, Sierra, Yukon Models

2001-2004 Oldsmobile Bravada

2005-2006 Saab 9-7X

with 4.8L or 5.3L VORTEC® GEN III, GEN IV V8 Engine (VINs V, T, M, B, Z -- RPOs LR4, LM7, LH6, L33, L59)

This bulletin is being revised to include engine RPO L59. Please discard Corporate Bulletin Number 06-06-01-019A (Section 06 - Engine/Propulsion System).

Some vehicles may experience a gradual coolant loss over time. A very low percentage of cylinder head(s) manufactured with an embossed Castech logo may develop a porosity crack in a very specific area.

Inspect the cylinder head assembly to determine if the casting was manufactured by Castech. This can be accomplished by inspecting for their casting logo located on top of the intake port, under the rocker arm support rail and in the spring deck cavity portion of the cylinder head.

Important: If the cylinder head(s) are Not a Castech casting, follow normal diagnostic procedures in SI to determine the cause of the coolant loss.

Important: If No evidence of coolant loss is found on inspection of Castech casting cylinder head(s), follow normal diagnostic procedures in SI to determine the cause of the coolant loss.

The crack location can be found in any of the five cylinder head(s) oil drains. This can be seen as a clean or shiny area, on an otherwise stained surface (1). Pressurizing the cooling system at this time may reveal coolant, air, or a combination, weeping in the described area. If inspection reveals evidence of coolant witness marks (1), replace the entire cylinder head(s) assembly.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

Document ID# 1986750

My truck is Vin code T, and RPO code LM7.

I took out the pictures of how to identify the castech heads to shorten the document down. I don't have any access to my tools where I'm currently living so I can't even begin to dive into the engine. My truck IS however under warrenty for 2 more months! So, if this is the issue, I need to get it taken care of right away!!

As I've read and understand it, the coolant can leak into the oil which could explain the smokey starts. the dex-cool and oil combine to make a sticky caramel like product potentially building up on the lifters and making the clicking/ticking sound. If i've done all my research right there are 1 of 2 potential problems: leaking head gasket, or bad heads. Either way, they should both be covered under the remainder of my 5 year 100,000 mile warrenty.

I can record a video with my camera of what this sounds like if anyone needs that to help their diagnosis.

I guess I'd just like to get this out there and see if I'm on the right track with this or if there's anything else I should try to track down before Monday. I'll be making a visit to the dealer Monday one way or the other.

I appologize for the long post, but I wanted to be as detailed and specific as I could to get an accurate diagnosis of the problem. Please give your opinions and thanks for all your help in advance!

Ben

mtm700 · October 3, 2009

Sounds like a cracked head to me. Good chance they both are cracked, and if only 1 is cracked, have the other replaced as well. In a few cases, the customers wanted their lifters replaced too. Never charged additional labor to do so, because the heads need to come off anyways to replace the lifters, they are easy enough to do.

ra8643 · October 5, 2009

I just went through this. Sounds verbatim on symptoms. It is a most likely a cracked castech head. A few notes:

-the ticking you hear is from bled-down hydraulic lifters - the coolant is leaking into the crankcase, thinning the oil, so they bleed down overnight

-the smoke is from the intake sucking up mucus'd up sludge every now and then from the top of the head (it only happens now and then)

-Dexcool sludges the oil, it does NOT turn it gray. Check your dipstick, the bottom inch is probably sludged. Your oil filter is likely full of sludge as well. When you drain the oil you will see chunks of crap at the bottom of the pan come out in the last few drops.

-Get this fixed quickly - you might be creating engine damage because you are running with thinned/sludged oil.

If I were you, I would change the oil, drive it a little and make sure your oil pressure has not degraded significantly. If it has, you have likely caused some rod bearing or main bearing damage already.

05silvycrew · October 6, 2009

Just an update, the dealer magically couldn't get any smoke on the startup, no ticking what-so-ever, and couldn't find any signs of a coolan leak anywhere! hmmmm, imagine that! ALL the symptoms that I've been dealing with just dissapeared overnight. maybe I should just keep my truck parked at the dealer lot all the time!! LOL

The service rep was pretty nice, and does believe me about the coolant loss. why shouldn't he, I've got a gallon and a half of Dex-Cool in my back seat. I told him to check the heads as per the TSB. If it's a cracked head or bad head gasket, I'm all set with my powertrain warrenty. If this comes back negative and there's no signs of a bad head (why am I thinking this is going to be the result) I'm into it for $200 of un-resolved labor costs. I just want my truck to be 100% again. I hate having anything wrong with it.

I'm supposed to find out tomorrow what the result is on the heads. I'll update tomorrow on the situation.

05silvycrew · October 7, 2009

update! Dealer gets the valve covers off, starts inspecting the heads and there is standing coolant! at which point finding the castech casting is irrelevant. he finally agrees that I've got cracked heads. new heads are being overnighted and I should have my truck back by the end of the week

Everything is covered under my existing 5 year-100,000 mile warrenty (which expires 11-26-09). glad I caught this now instead of 2 months from now!

special thanks to this forum for the search engine and all the experts that help us diagnose our problems.

txab · October 7, 2009

It would still be nice to know if they are the suspect heads or not. Find out if they are the referenced heads if you can.

05silvycrew · October 8, 2009

will do. I'll know for sure by the end of the week (service rep is out today)

KMGZ400 · October 9, 2009

does anyone know if this is a common problem with the 5.3? i havent had any engine problems at all with my suburbans 5.3 with about 140k on it.

txab · October 9, 2009

I don't think I know of anyone personally that has had this problem, and I know a lot of people with vehicles in the affected group. It would be interesting to know how many heads have been affected.

mtm700 · October 9, 2009

There's a TSB on it, so that says it's happening to quite a few people and is a common issue. I know 7 people personally that had this issue.

txab · October 9, 2009

There's a TSB on it, so that says it's happening to quite a few people and is a common issue. I know 7 people personally that had this issue.

I'm still curious as to numbers. I know it is occurring. I own 2 in the group. I've got maybe 10-12 friends that have vehicles in the group. There are 26 vehicles sitting in our yard right now that are in the group as well. None have any of the problems nor do they have the suspect heads. I know several people from different websites have had the problem. Plus add to this, I was in the machine shop the other day picking up one of my blocks that was being machined and I noticed a set of GM aluminum heads from a 5.3. They were cracked and they weren't in the TSB group. Just wondering what the frequency and actual distribution of this problem is.

mtm700 · October 10, 2009

What casting or casting number were the heads in the machine shop?

05silvycrew · October 10, 2009

well here's an update....and to say I'm a little pissed would be an understatement!

Service Rep. was supposed to order and overnight the parts Wednesday. He told me that my truck will be done by the end of the week. Thursday came and left, Friday came and I never got a phone call. So, on my way back from my wife picking me up from work we swung by the dealership. After going through 3 different personel (none of which were the SR I talked with) and waiting 20 minutes for an answer this is what I got....

"It looks like we're still waiting on parts, they SHOULD be here on Monday. But if they're not here Monday, they SHOULD be here Tuesday. And it looks like we're going to have a full day working on it. Soooooo, we SHOULD have your truck back to you no later than Wednesday night"

I about fell over in shock!! no phone call or even an attempt to contact me and they were just going to leave me hanging??? On top of that, I asked if I could have a loaner vehicle until the work was done and because it was after hours (I showed up at 5:29 and they close at 5:30) he claimed he couldn't find anyone to get me a loaner. but I COULD come back Monday night and get one then! gee thanks.

This was my first visit to this new dealership, and likely my last. I can't believe the poor customer service.

Sorry to rant, but I needed to get that out.

KMGZ400 · October 10, 2009

yeah i tend to go to the same dealership where i know the people who work there for reasons like that.. i know a least 4 other people with 5.3's with over 70k on them and no problems.

05silvycrew · October 12, 2009

the saga continues......

call to get an update today. "well we got the heads in today, but we didn't receive the gaskets or new bolts. Soooooooo best case scenario, if we get those tomorrow, we SHOULD have this buttoned up for you by Wednesday"

as i take this in, I patiently wait for the Service Director to offer me a loaner vehicle. He doesn't. I politely ask that since they've had my truck since last Monday...and it was supposed to be done by Friday....and nobody tried to contact me to let me know the parts haven't even come in....and my wife and I have been sharing 1 vehicle for the past week....if I could get a loaner vehicle until the work was finished. He says "SURE! that'll be no problem. Can I put you on hold?" so I'm waiting and waiting and waiting....he comes back on the line. "uhhh, I can't seem to get ahold of anyone right now. can I call you back?"

at this point the whole thing has become comical to me and completely unbelieveable at the same time. So as I've been sitting here (waiting for my wife to pick me up from work) for the last 30 minutes, I'm wondering if I'm ever going to get my truck back???

will post another update, whenever....if ever.....there is one.