is the 3.5L 6 cyl 1994 LHS an interference engine?

The 3.5 is not an interference engine.

According to the Gates Timing Belt Replacement Guide

- click the pdf link - give it time to download even if it acts like it's done), it *is* an interference engine. Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

It is an interference engine, that's why if you ever set up the timing marks at top dead center with the heads off you will see that the piston is not really at TDC. The reason behind that is because if the cam rotates while installing the belt the valve could slam into the piston and cause damage. The marks were offset to prevent this.

It's not. Just let folks that have broken their belts answer and that way there's no confusion.

Is that true specifically of 94's? I may have read discussions on this in the past in which it was concluded (at least by some) that certain years were iterference, others were not (even though the Gates guide shows them all as interfeence).

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Yes.

The Gates book has its share of errors. (in this case, errors sell timing belts)

I've replaced scores of these belts and not a one ever bent a valve. That is more than a coincidence.

My Mitchell On Demand lists the 3.5 as a non-interference engine, it also lists the 3.2 as an interference engine. The Mitchell text is direct from ChryCo.

The engine has been out what, 13 years now, yet I have yet to see anyone post a complaint of a 3.5 with bent valves in -any- appropriate newsgroup, plenty of incidences posted for other engines that -are- interference though.

Thanks for all of the replies. I'm in the process of taking a cautious approach. I'm going to replace the timing belt. I'm going to leave off the harmonic balancer and the accessory belts. Then I'm going to start the engine. If it seems to run ok, then I will replace the water pump and finish the job.

Random

aarcuda69062 wrote in news:nonelson- snipped-for-privacy@newsclstr02.news.prodigy.com:

Apparently DC is schizophrenic on the point. You say Mitchell quotes Chryco as saying the 3.5 is non-interference. If that is correct (and applies to all years/versions), FWIW (apparently not much) my '99 LH-car FSM (on page 9-71 - 3.2/3.5 Engine Components - and page 9-100 - 'Timing Belt Removal') has bold text warnings: "NOTE The 3.2/3.5 are a NON [their emphasis] free-wheeling design" and "Caution: The 3.2/3.5L are NOT [their emphasis] freewheeling engines. Therefore care should be taken not to rotate the camshafts or crankshaft with the timing belt removed" respectively.

As an added piece of confusion, there are several threads on the 300M Club forums where this question is discussed. Here's one of them:

ja300mes is a DC dealer tech and Red Baron is an ASE certified master mechanic and fleet manager and holds the 1/4 mile track record for normally aspirated 300M's - they both say it's interference (at least for 2nd gen cars). I'm not disagreeing with you - I've just seen convincing claims on both sides. I'm still wondering if there are maybe some year-to-year differences that may be causing at least some of the contradictory claims by apparently equally qualified people.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Dunno Bill.

The FSM lumps the 3.2 and 3.5 service information together, perhaps they felt that a blanket statement about the engines being interference would be easier for their mechanics to digest than if they only called out the one that actually is.

My Gates guide lists all 3.5s as non-interference and I have yet to see or hear of a crashed 3.5 due to a timing belt mishap, and I have had them towed in with the belt wrapped around the crankshaft pulley, they ran fine after repair. Brother in-law works at the local Dodge dealership part dept, he has never seen a 3.5 need the heads pulled because of a broken timing belt.

It's also possible that the OEM belt supplier and myself are wrong...

Oh boy - more contradictions from one source. The on-line Gates T-belt manual

shows all 3.5's as interference. Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Fun isn't it?

Gleaning accurate service information (even from the OEMs) is a

-big- issue in the industry.

When I owned my 94' LHS I bought the factory service manual. I also know a tech who works for Chrysler and is factory trained. They both said that the

94' 3.5 engine was NON-INTERFERENCE. Yep, NON. They changed to a interference engine in the next generation of 3.5 engine design. I read that as a press release on Chryslers main page when the 300M was released. That engine had 250hp (in HO trim). The original 3.5 was 215hp.

Steve M.....

Gates is wrong (actually, they're wrong an alarming amount of the time). The first-gen 3.5 is very definitely a free-wheeling engine.

WRONG!!

This is not a second-generation (aluminum block) 3.5

It is an IRON BLOCK first-gen 3.5- no interference.

Only the aluminum-block 2nd-gen engine is *possibly* interference (and I'm not SURE that it is). The first-gen iron-block engine (1993-1997) is DEFINITELY NOT an interference engine.

replying to Bill Putney, robust two wrote: the timing belt went bust on my 1994 chrysler lhs what are the chances of valves being bent? does it pays to take a chance?