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Upper Radiator Hose Collapsed

Make 'em Last
11-30-2009, 02:31 PM
While revving the engine (at operating temp) during a fuel pressure test ('99 Intrigue 3.8L Series II 168K), I noticed the upper radiator hose collapsing. After letting it cool down, pulled the radiator cap & observed the level down 1 - 2 inches from top of the radiator neck. Topped off the coolant and replaced the cap with a new, 16# one. (There was plenty of coolant in the reservoir, and the car has not been running hot.) Drove the car 5 miles, filled the gas tank & returned - temp ran 197-198 deg. (ScanGauge). Upper hose is still much flatter than normal.

Anyone ever seen this? Should I bother replacing the upper hose (sure it's been replaced before, but not sure how long ago)?

11-30-2009, 06:31 PM
Replace the hose again. A hose goes bad from the inside out. When they start to collapse it usually indicates that the hose has gone soft and will probably fail. Also make sure that the fluid level remains at optimum levels so that the hose remains full at all times as well.

11-30-2009, 10:18 PM
This thread should be moved to the Olds Intrigue forum!

12-01-2009, 01:03 AM
This thread should be moved to the Olds Intrigue forum!

Bo we allow '98-'99 Intrigue owners with the L36 Series II 3800 to post here and there is a link from Intrigue to Grand Prix for Tips & Maintenance.

Make 'em Last
12-01-2009, 08:49 AM
Thought this question was related more to 3800 Series II than to Intrigue. Often debate which forum to post a question to (Grand Prix versus Intrigue). Will review "Attention '98-'99 Intrigue Owners with SII 3800 Engine (" by BNaylor. Please move where appropriate.

12-01-2009, 09:15 AM
Your post is fine here so it will not be moved. Out of curiosity what brand was the upper radiator hose? Also, what are the details on your past hydrolock issue and what was replaced?

12-01-2009, 12:39 PM
also, a weak t-stat will cause an upper hose to collapse. It may be opening enough to keep the temps down, but not enough to allow full flow causing negative pressure to build up.

Make 'em Last
12-02-2009, 10:38 AM
Current upper hose is either Advance Auto Parts or AutoZone store stock. Both store's online listings show about $10 for generic, but do see a Goodyear hose for about $20 - guess it pays to get the brand name. Haven't checked dealer part for pricing, but will before I purchase. Do you have a brand to recommend?

Ok. Think I'll replace the t-stat while I'm at it. Do you have a favorite brand in mind? I've always stayed with the OEM temp, and in this case it's 195 degrees. Any of you have long-term success with a lower temp t-stat?

Ah, the UIM saga. Suppose it's the classic story for Series II. Began losing small amounts of coolant, and scratching my head searching for where it was going. As we all know, problems don't go away - they get worse. On a trip to San Antonio I noticed the car running hotter than norm. On the way back seemed to miss under load, and barely made it to the home driveway. Intrigue literally hydrolocked as I pulled in the driveway, when the rpms became less than what was needed to overcome the coolant leaking into the cylinders - think there were 2 affected.

Reasearching the problem lead me to online searching & auto forums - that's when I found Automotive Forums. Confirmed my UIM had the EGR port issue (material deteriated & cooling orifices bled onto EGR orifice). Here are the parts I obtained for the job: Intrigue '99 3.8L Series II UIM & LIM Prep Questions (

Replaced the UIM and cleaned/reused the LIM. Used an ARP 5/16-18 thread cleaning chaser for the LIM holes in the block and Loctite thread sealer on the UIM bolts - reused all bolts. The write-ups/getting new coolant elbows sure helped.

Main problem I had was after the repair. Plugs were out, and engine turned over fine. Installed the plugs, ran the engine for about 30 seconds, and when I started it again it locked. Wouldn't turn over. Ended up being the starter. Damn thing went out (pinion jam against flywheel) at just the right time to make me think the engine mechanically broke due to the hydrolocking.

Well, have a couple thousand miles on it now. And (knock on wood) no problems resulting from the failure or repairs. My thanks to all the folks who share their wisdom on this and other forums!

12-02-2009, 07:12 PM
Funny how your started took the perfect second to go out on you. It sometimes happens like that.

12-02-2009, 07:13 PM
Goodyear or Gates are the brands I would recommend. I would also recommend a Failsafe thermostat. It is more expensive but if it fails it will fail in the open position so that the engine does not overheat. Cheap insurance against engine damage.

12-02-2009, 08:01 PM
So when I do a thermostat for the GP I will use the failsafe. Never knew that they had the thermostats like that.

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