Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Overheating Puzzle

Thread Tools
 
Search this Thread
 
Old Jan 17, 2008 | 09:03 PM
  #46  
ErnestSw's Avatar
ErnestSw
Rennlist Member
 
Joined: Mar 2003
Posts: 4,328
Likes: 0
From: Nashua, NH
Default

If you can collect some of the gorilla snot you can experiment with it. You can try a citrus based cleaner, detergent, Dawn, or whatever to see which one dissolves it best.
Reply
Old Jan 17, 2008 | 09:51 PM
  #47  
dr bob's Avatar
dr bob
Chronic Tool Dropper
Lifetime Rennlist
Member
 
Joined: Oct 2001
Posts: 20,506
Likes: 565
From: Bend, Oregon
Default

You might want to try Liquid Tide laundry detergent if you need to get foreign residues out of a cooling system. It's pH-neutral, rinses pretty clean, and does a good job on most stuff that normally finds its way into the cooling system loop. Old coolant and ATF/Motor Oil contaminants sre no match for Liquid Tide. The 'with bleach' version uses enzymes and an obviously-weak peroxide that work when allowed to stand warm for an hour or three. Plus the water softeners will grab on to loose calcium and sodium salts and let them flush out a little more easily. Much Safer than that Draino option mentioned previously.
Reply
Old Jan 17, 2008 | 11:19 PM
  #48  
Mrmerlin's Avatar
Mrmerlin
Team Owner
20 Year Member
 
Joined: May 2004
Posts: 31,237
Likes: 4,221
From: Philly PA
Default

I wonder if cleaning out the cooling passages with anything might also reveal a headgasket leak ??. Since your into it this far I guess you might as well continue, if you develop a headgasket leak then you might be at the root cause of these cooling problems
Reply
Old Jan 17, 2008 | 11:26 PM
  #49  
dr bob's Avatar
dr bob
Chronic Tool Dropper
Lifetime Rennlist
Member
 
Joined: Oct 2001
Posts: 20,506
Likes: 565
From: Bend, Oregon
Default

Stan--

The overheating at idle and cooling with the engine rev'd probably points away from a headgasket failure. Generally, headgasket problems multiply as load increases. My nickel (devaluated to too sense thanks to US economic policies...) says that the water pump is a key part of the problem.
Reply
Old Jan 18, 2008 | 12:59 AM
  #50  
928ntslow's Avatar
928ntslow
Thread Starter
Addict
Rennlist Member

 
Joined: Aug 2001
Posts: 4,172
Likes: 9
From: Portland, Oregon
Default

Hmm...lots of chatter since I left.

Back now. Good news, Success!

So here's what I did. Oh and I digress for a moment. There is no "bridge" or cross-over at the rear of the block as I had implied in my previous post.

At the back of the head on the driver side, there is a cover over what would be an outlet for the heater valve on a RHD. Both heads have them and the US cars have the heater valve obviously located on the passenger side. I looked at the proximity of this access compared to the drain plug and it is virtually located right above.

I put the old WP back on just to plug that hole, put the drain plug back in the passenger side and filled with smokin' hot water. BTW, I had removed the T-stat so I knew I was full if water spilled through the overflow at the bridge.

ADDED: Forgot to mention that I stuck a longer piece of tubing down the access attached to the compressed air and zapped it several times. I worked it down as far as I could hoping to get into something that would get stirred/loosened up from the air.

I then started using a plastic zip-tie as it was flexible enough to make the turn in the drain plug. All I kept getting was what looked like wet mud at the tip of it. I then got out the coat hanger and did some bending. Worked it in there and the next thing ya know, I was getting a dribble. I kept working it until finally the dam broke. I got another bucket of scorching hot water and filled again, but this time, I used the fitting I had made with the compressed air hooked up. Filled again and hit it with several hard pops of air and some steady ones. Removed the fitting and drained. Then drained the other side again.

Not sure whether there was one thing that did the trick or all combined, but I'm a happy ****!!!

I will have a new WP and other items tomorrow to get it all back together. Incidentally, I even put the T-Stat in boiling water tonight to make sure it works...which it does quite well.

Once I get everything back together, I will most definitely do a serious system flush. Thanks for the advice on that.

Note the pics below and the crud that came out of the block. I think there was calcium, rust, a gummy bear and possibly a couple of Smurfs, but i can't really say for sure.

Thanks for the support everyone. I can only hope that my request for help on these things helps others as well, now and later.




Last edited by 928ntslow; Jan 18, 2008 at 04:15 AM.
Reply
Old Jan 18, 2008 | 01:43 AM
  #51  
borland's Avatar
borland
Drifting
 
Joined: Aug 2003
Posts: 2,259
Likes: 3
From: Camarillo, CA, USA
Default

I guess that water pump was being used also as a meat grinder.

Something foreign apparently ground down to mush.
Reply
Old Jan 18, 2008 | 04:31 AM
  #52  
marton's Avatar
marton
Drifting
 
Joined: Nov 2001
Posts: 2,233
Likes: 1
From: zürich, switzerland
Default

On the foto it looks like you found the eggs of some rare & exotic water dwelling creature.

well done on getting the coolant flowing out of the drain holes; do not remember all the posts but I assume you will give the new radiator a good & seperate flushing before you button everything back together??

Marton
Reply
Old Jan 18, 2008 | 09:03 AM
  #53  
Dennis Wilson's Avatar
Dennis Wilson
Drifting
 
Joined: May 2001
Posts: 2,747
Likes: 3
From: Owasso, OK
Default

Meat grinder? Maybe you found Hoffa. LOL

Dennis
Reply
Rennlist Stories

The Best Porsche Posts for Porsche Enthusiasts

story-0

Talos Takes Your 991 Porsche 911 GT3 to the Next Level for a Cool $1.13 Million

 Verdad Gallardo
story-1

9 Vehicles Porsche Helped Engineer that Aren't Porsches

 Verdad Gallardo
story-2

9 Features and Characteristics That Only Porsche People Understand

 Verdad Gallardo
story-3

I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

 Joe Kucinski
story-4

10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

 Verdad Gallardo
story-5

Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner

 Joe Kucinski
story-6

This Builder Is Turning Heads With Its Slantnose 911 Creation

 Verdad Gallardo
story-7

Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture

 Verdad Gallardo
story-8

Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look

 Verdad Gallardo
story-9

10 Porsche Colors That Have More Personality Than Most People

 Verdad Gallardo
Old Jan 18, 2008 | 02:20 PM
  #54  
Tom. M's Avatar
Tom. M
Deleted
Rennlist Member
20 Year Member
 
Joined: May 2001
Posts: 5,657
Likes: 312
Default

looks like sand and oily dirt mix..when the last owner did a waterpump job and a big clump of oily mess fell into the block...and it was like "..ahh..no big deal..it won't affect anything". Button her up and send her out..

Sounds like you cured your issues..good deal...

later,
Tom
89GT
82 Track Car in progess
Reply
Old Jan 18, 2008 | 02:39 PM
  #55  
Dennis Wilson's Avatar
Dennis Wilson
Drifting
 
Joined: May 2001
Posts: 2,747
Likes: 3
From: Owasso, OK
Default

Keith,

All the crud around the drain plugs are an indication of other junk in low spots throughout the engine or heater core plumbing. I would still backflush with or without cleaners to clear out any remaining debris.

Dennis
Reply
Old Jan 18, 2008 | 02:54 PM
  #56  
Adam Geist's Avatar
Adam Geist
Rennlist Member
 
Joined: May 2007
Posts: 323
Likes: 0
From: Not that far from the Jersey Shore
Default

Hi - I spoke to my brother (also a 928 owener) who is a former cooling systems engineer. The "fish eggs" and jelly stuff is actually the glycol that separated out of the coolant.

Based on the info in your post, he said the car probably sat for a long time (several years) and coolant was not changed for several years. When coolant is not changed out for several years, the stabilizers that bond the water and glycol together break down. What happens next is the glycol and water separate. The glycol turns to a jelly-like consistency and sinks to low lying areas in the cooling system and the water "floats" on top of it. That's why the water pump impeller has rust on it and any other metals in the cooling system would have rusted too (metal y-pipe on the passenger side fender well?).

Before using a detergent or flushing solution, put some of the "fish eggs" and hot water in a jar with a lid and shake it up. If the "fish eggs" dissolve, then a detergent/flushing solution is not neessary. Install a new water pump, fill the cooling system with water, run up the temp and drain. Repeat several times.

Also, check for a head gasket leak as the cylinder heads are made of A356 alloy which is softer than the block (A390 high silicon alloy). I would not be surprised if the cylinder heads/gaskets are corroded.

Adam
Reply
Old Jan 18, 2008 | 03:12 PM
  #57  
heinrich's Avatar
heinrich
928 Collector
Rennlist Member

20 Year Member
 
Joined: Jan 2003
Posts: 17,270
Likes: 5
From: Seattle
Default

I have used only phosphate-free coolant for many years and have found NO green coolant available here locally, that wouls meet the requirements of our engines. So, I use the Dexcool .... If I see green, I assume it is crap, and toss it. No way to tell if it's good or bad green. And Bill, I have never had the orange stuff leech
Reply
Old Jan 18, 2008 | 03:49 PM
  #58  
AO's Avatar
AO
Supercharged
Rennlist Member
20 Year Member
 
Joined: May 2002
Posts: 18,926
Likes: 88
From: Back in Michigan - Full time!
Default

Keith... again sorry for the hijack...

Since I brought up the "green coolant = bad juju" comment I guess i should explain myself.

I didn't realize that the coolant in this car was fresh, so I appologize for jumping to conclusions. However, as recently as 2-years ago, the green coolant being sold at my local auto parts store was not phosphate-free. There may have been brands available that were green and phosphate-free, but my store didn't have it.

However, when I was recently there to pick up some coolant for my rebuild, I noticed that all of the name-brand green coolants specifically said "Safe for All Engines" and when I looked at the ingredient list, I did not see any mention of phosphates in their chemistry. I did not look at the house brand.

That said, I decided to stick with the DexCool. Mark it up to personal preference, I guess.

So to sum it up, I agree as long as the coolant is phosphate-free, it should be good for our cars regardless of the color. However if your coolant is more than a couple years old and is green, you should seriously think about changing it before it potentially eats your heads.
Reply
Old Jan 18, 2008 | 03:56 PM
  #59  
marton's Avatar
marton
Drifting
 
Joined: Nov 2001
Posts: 2,233
Likes: 1
From: zürich, switzerland
Default

HTML Code:
as recently as 2-years ago, the green coolant being sold at my 
local auto parts store was not phosphate-free.
Don't tell me the guy at your local parts store has 6 fingers & plays the banjo?

Luckily I am partly colour blind so I always have to read the small print on the label.

Marton
Reply
Old Jan 18, 2008 | 04:05 PM
  #60  
heinrich's Avatar
heinrich
928 Collector
Rennlist Member

20 Year Member
 
Joined: Jan 2003
Posts: 17,270
Likes: 5
From: Seattle
Default

Marton what's with the HTML code in youe replies?
Reply



All times are GMT -3. The time now is 06:17 PM.

story-0
Talos Takes Your 991 Porsche 911 GT3 to the Next Level for a Cool $1.13 Million

Slideshow: Talos Vehicles has transformed the Porsche 911 GT3 RS into a carbon-bodied, race-inspired machine that costs well over $1 million before the donor car is even included.

By Verdad Gallardo | 2026-05-19 13:39:04


VIEW MORE
story-1
9 Vehicles Porsche Helped Engineer that Aren't Porsches

Slideshow: Long before engineering consulting became trendy, Porsche was quietly helping other automakers build everything from supercars to economy hatchbacks.

By Verdad Gallardo | 2026-05-15 12:44:44


VIEW MORE
story-2
9 Features and Characteristics That Only Porsche People Understand

Slideshow: Some brands build cars. Porsche builds traditions, obsessions, and a few habits that stopped making sense decades ago but somehow became part of the charm.

By Verdad Gallardo | 2026-05-13 18:46:13


VIEW MORE
story-3
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

Slideshow: Six years and 500 Rennlist articles later, these are the biggest changes at Porsche.

By Joe Kucinski | 2026-05-11 09:52:55


VIEW MORE
story-4
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

Slideshow: Some Porsches exist for very specific reasons-others feel like they were built just to see if anyone would notice.

By Verdad Gallardo | 2026-05-06 18:00:32


VIEW MORE
story-5
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner

Slideshow: Choosing between the 911 GT3 S/C and 718 Spyder RS in 10 key categories to determine one surprising winner.

By Joe Kucinski | 2026-05-05 12:51:46


VIEW MORE
story-6
This Builder Is Turning Heads With Its Slantnose 911 Creation

Slideshow: A small Polish tuner has reimagined the Porsche 911 Slantnose for the modern era, blending 1980s nostalgia with widebody tuning culture and serious performance upgrades.

By Verdad Gallardo | 2026-05-01 10:49:43


VIEW MORE
story-7
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture

Slideshow: Porsche has created a Japan-only 911 GT3 Artisan Edition that blends track-ready hardware with design cues inspired by traditional Japanese craftsmanship.

By Verdad Gallardo | 2026-04-28 19:37:40


VIEW MORE
story-8
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look

Slideshow: Porsche's latest electric Cayenne Coupe blends dramatic styling with supercar acceleration, turning the brand's midsize SUV into a 1,139-horsepower flagship.

By Verdad Gallardo | 2026-04-27 19:39:30


VIEW MORE
story-9
10 Porsche Colors That Have More Personality Than Most People

Slideshow: Porsche's wildest paint colors aren't just shades-they're full-blown personalities on four wheels.

By Verdad Gallardo | 2026-04-27 19:38:13


VIEW MORE