[DayDreamer]

My HCV popped this morning in the traffic.... Very impressive steam cloud..[img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]. Luckily I was a mile from my Mac. Dropped the car off and had to go home and fetch the other Porsche..... some days are really tough [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img].

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[PorscheDude]

Life is good....

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[Anchorman]

Most of us carry spare HCVs - and most of us don't have spare Porsches. Good save!

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[DayDreamer]

spare Porsche... [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]. never thought of it like that...

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[josephsc]

Welcome to the "blown HCV" club! It's one of those sure to happen items on the 968, it seems. Many of us have replaced the plastic piece with a metal one from an Audi. if you can source it, you might consider it.

BTW, have you popped the clutch hose, yet? That's another one of those things just waiting to happen....

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[PorscheDude]

I don't carry a spare HCV, heck I don't even keep one in my stock pile of spare parts.
But I do have a spare Porsche at the minute.
Hopefully the 968 will change hands in the week.

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[apex]

Spare porsches!?! That would be nice. [img]style_emoticons/<#EMO_DIR#>/biggrin.gif[/img] I do have a spare HCV, but haven't considered carrying it in the car - until now. Seems like that, and a spare DME relay are essential parts of any road kit.

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[Lonestar968]

Please enlighten me. What the heck is an HCV, a heater core valve?

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[PorscheDude]

close....

heater control valve. its the round plastic thing on the far side of the distributor above the exhaust manifold..

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[968Syncro]

Figured I'd do a "bump" on this subject to get it into the "View New Posts" area, mine popped yesterday creating a big hassle during an all day planned use of the 968. Didn't ruin the day, but created uninvited complexity such as: "Dad, why do you always have these old cars!".

So this is a reminder to everyone to please replace yours or carry a spare HCV (or bypass pipe) and not wait until the 968 makes a "suggestion".

Thanks to PorscheDude for listing the part numbers for the high quality item Here. My local NAPA has it, $16.99 can save you a lot of trouble.

Roland

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[94SilverCab]

Pete at RS Barn is not a fan of the full metal replacement, though I know that many have used them successfully.

My plan is to change it every 5 years as "standard maintenance" and not have to worry about it.

JMHO,

Jay

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[968Syncro]

Jay,

Are you aware of any details why there may be disadvantages of the full metal version? Thanks!

Roland

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[jfrahm]

I've had no trouble with the metal valve option other than having to put a twist of wire or a ziptie on the vacuum line to keep it snug. There are at least two designs but either of them seem a lot less likely to break in half and soak the RF tire with coolant than the OEM plastic piece.


-Joel.

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[Cloud9...68]

I also replaced mine years ago with a metal one (from an '80s Audi, I believe), and have had no problems. I wonder what Pete's concern is. Given his expertise, I'm very curious. Regardless of which valve you go with, but especially if it's the plastic one, Design 1's heat shield is a very good idea to keep things cooler in this area of the engine compartment.

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[Mark]

The plastic ones generally last over 10 years so that's enough for me. [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

The flow pattern on the metal one has at least one extra bend in it.

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[94SilverCab]

I'll ask Pete to chime in, something to do with the flow in the plastic HCV being a guilotine and the metal hcv being a louvre and perhaps obstructing some flow. As I said earlier, many folks have used the metal HCV with no difficulty.

Jay

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[banditsc]

I have the metal one also. The flow would only cause an issue for the heater, and my heat gets plenty warm enough, warm enough to keep me toasty with the top down.

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[flash]

yeah - the only real issue i saw with it was fitment and more than that, the vacuum line - i hate vacuum leaks, and that one looked problematic, as it was a different size fitting - the problem with these cars is that they will still seem like they run almost normally with a minor leak, so there is no way to tell if it's there or not, but vacuum leaks can cause problems

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[banditsc]

Ya, the vacuum line was the only thing I saw. With mine the fitting was so long after I straightend it out that I was able to put a lot of the vacuum line on it so it's tight. Another option others have done is to enlarge that fitting with some JB Weld. Or just stick with the stock one..

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[SILVY968]

I had my HCV blow about 2 years ago and replaced it with the stock plastic unit. Then we discovered the metal unit so I bought one and kept it with my spare DME relay in the trunk.

Surprise! no point in carrying it since it takes tools and coolant to get you back on the road.

Last weekend I was out for a mountain drive with the top down and BOOM, STEAM, coolant smell as the plastic valve let go again!
They all seem to open up at the same place, where the 2 halves glue together. Stupid design that puts pressure from hot coolant directly out of the water pump into a glued, plastic part with it's valve closed in warm weather.

AAA and a flatbed got me home to put in the metal HCV and more coolant.

Moral of the story?
Buy a metal unit and put it in before the warm weather, you will be sorry if you don't. Either they do not make them the same as in 1995 or I was just unlucky, but having a better piece and not installing it made me feel really stupid.

P.S. Installing flash's heat shield may heat up this area a bit more that normal, causing the plastic HCV to fail. I don't know, but I only mention it since I did install the heat shield a few months ago. I am keeping my heat shield and am a strong advocate of the metal HCV.

I got new 0.1250" (3mm) ID, thick wall high performance silicon vacuum lines, as this operation caused the old, brittle vacuum line to break. The new silicone hose has a wall that is thick enough to bend around to the metal HVC without any problems. The stuff is also available in colors to match "spiffy" spark plug wires. www.siliconehose.com

Brian

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