Pontiac bonneville intake manifold issue

[greenwar]

Heres the deal, I am freaking interested in owning a GM car with the Fireball (3800 V6). Preferably a 4 door sedan. (manual is out of question so I will settle with automatic). I did some research in 1999 Bonneville (price was right) and found out that there is an intake manifold leaking issue which causes premature engine failure.

I saw GM did a recall on some of the vehicle containing 3800 v6, but 1999 bonneville was missing. However 93-98 and 00-03 were in the list. I am wondering if 99 Bonneville is immune from this intake manifold issue.

Any body out there who owns a 99 Bonneville - let me know if you encountered the intake manifold leaking issue. Also any idea how much it costs to replace the manifold anyway just as a pre-emptive measure?

Post away... with the useful info ofcourse.

 

[Adica]

That's weird, I may be the only one. I own a 99 pontiac bonneville. I love it. I just had it detailed as a matter of fact. Anyways, there was a recall on it a couple years back. I think it was for the manifold actually....but no quite positive. Anyways, it runs great, has no problems. Get one, they're great!

 

[thecritic]

Nearly all of the GM 3.1L and 3.4L 60-degree V6 engines have intake gasket issues. An updated part, featuring a revised torquing sequence for the bolts, as well as a metal gasket, has been out (by GM) for the last year or two that completely resolves the problem. Thus, many cars made up to 2004 featuring the 3.1L and 3.4L engines have the intake problems. 2005 and later models should be OK.

The 3.8L V6 has had its share of intake manifold gasket leakage, but no where to the same extent as the 3.1/3.4. I think there's an updated part avaliable now for the 3.8L by GM and/or Feltpro that will fix the problem should it leak at all.

Best advice I can give, if you buy a 3.8L, is to add a full pack of GM cooling system sealer pellets to a RADIATOR HOSE, NOT surge reservoir immediately. They will act as "insurance" against leakage and are completely harmless...GM uses them in all of the older Northstar engines. They are basically ground-up ginger root/walnut shells...not kidding. Do periodic oil analysis (www.oaitesting.com; www.blackstone-labs.com) to check for coolant leaks.

Again, the 3.8L isn't leakproof, but the chances of leakage are much less compared to a GM 3.1/3.4. Add the sealer pellets following a service with new coolant, with periodic oil analysis, and you'll be fine.

Hope this helps.

 

[greenwar]

wanmichael - thats a very informative reply. Thanks a lot. I was under the impression that 3.8L was the main culprit. My friend has an 02 impala with the 3.4L. I already warned him about the issue and will let him know of the cooling system sealer.

Hows the transmission on the bonnevilles? I know the 3.8L is a really long lasting motor apart from the intake issue. Are the transmissions durable enough if well taken care of say tranny flash every 20K miles with a new filter?

 

[thecritic]

You can pretty much guarantee him that his will leak...if it isn't already. Best way to tell is to purchase an oil analysis for about $20 and post it on theoildrop.server101.com (I'm "the critic" over there).

As for the 4T65E transmission, I'll show you what my transmission guy told me:

"The GM Hydramatic 4T65E has a lot of potential, but unfortunately at its '98 introduction up until 2002, they had PC (pressure control) solenoid quality problems, causing codes and slipping, sometimes complete failure.

They tend to wear the 4th clutch hub splines prematurely, (< 120,000 miles) and have significant vb wear problems due to calibration issues.

The 4T65E has the "right stuff" but a couple weak areas that bring it in before its time (<100,000 miles). Luckily GM is addressing some of these issues on current production units and may have a excellent unit now. Shift quality is very decent on these units."

That pretty much "answers" your question. A shift kit/recalibrated VB may help you here. Yes, do a pan pull/filter change with about 7.5 quarts of new Dexron-III(H) or DexronVI every 30,000 miles...that's your best defense aside from driving gently. A cooler can always help, along with an in-line filter, both of which can be purchased from www.bulkpart.com for very low prices.

 

[greenwar]

Wanmichael, thanks for the tips/info. Man you are knowledgeable. I will keep your suggestions in mind.