3.4 engine rotation to gain better access

[Cressidaadr]

I am gearing up to replace my intake manifold gaskets and rear spark plugs this weekend on the Venture and it will be the first time I have had to rotate the engine. (Other times shop has done the work but I need to save some $$ now or not much of a Xmas)

I have reviewed the steps as mentioned in the Haynes manual but I plan on driving the front end up on ramps or at least raising the front on jack stands so I will not have to be bending over as much when I work on the engine. My question is will using the ramps make it much more difficult for me to get the engine to rotate forward - I am thinking it may mean pulling the engine uphill due to the elevated front end ?

And, I think I read someone put their van in park and then pushed on the body which resulted in the engine rotating ? No doubt if it is on the ramps I will not be able to push on the van - anyone use this method please explain a bit more details.

I plan on using a rope or small ratcheting strap to pull (rotate) the engine forward and then tie it off somehow to hold it in position. Maybe it will all seem rather simple once I do it once but I have a hard time understanding how it could be easy to get an engine to rotate so I am looking for any problems to watch for or other suggestions to get this engine in the rotated position.

Last, if I get an air ratchet will it make this job much easier/faster than just using hand tools ?

Thanks in advance.

[Schrade]

I did this in mine before mine got folded up in the accident, and I don't remember anything special about the work - it was over 2 years ago. Some of my Venture posts I can hardly remember too, except that firewall vent nipple. Incredible detective work, and help... WON'T forget that!!!

I DO remember having so much stuff in place to MAKE SURE the engine didn't rotate back on my fingers while I was doing the work, that it was almost in the way. Didn't mind a bit tho', cause it was for safety.

I can't remember if I had something behind the engine too - 2x4 against the firewall???

[merc81]

This is really not a big deal at all. The engine will rock freely back and forth once you disconnect the engine mount screws on top. For extra motion, loosen or remove the two lower engine mount screws under the engine (under the flywheel).

The entire engine/transmission will roll back and forth so there is the issue of the wheels needing to turn if you have it in park. Block the rear wheels & /or use the parking brake and leave it in neutral to avoid this problem.

There is way more room than you need if your are pulling the lower intake manifold. You will need to remove the alternator and power steering pump, then the coil pack back there, and once those items are out of the way, king kong could fit his arm in to get at the spark plugs.

I wouldn't put the van on ramps. What I do is remove the engine mounts entirely from the frame over the radiator, then put a rug scrap over it to soften the floor so to speak and lay my belly on the frame where the hood mount used to be. You will not be in there as much as you would if the heads were coming out so don't worry about the back strain.

John

[bigcoconut]

DITTO - merc81

I've done the same thing. Put the tranny in Neutral, disconnect the top engine mounts (big silver thingies above the radiator) and pull the engine forward. I used a motorcycle tie down strap to one of the engine lift "D's" and the front frame behind the bumper and cinched the engine in place.

Once there I pulled the wiper arms (under the cowling), coil packs, brake vacuum hose, and MAP sensor (black vacuum thingy under the coil pack plate) and had plenty of room to get to the rear plugs.

Be advised, double and triple check your plugs and wire connections on the backside. Also, the MAP sensor (under the coil packs) has two vacuum hose connections side by side, one is just a hair bigger than the other, be very very sure as to what hose goes where when putting it back together. I screwed that one up and it took me awhile to find my SNAFU. I had a miss problem after my tune-up and had to do the whole engine rotation thingy twice more to diagnose what I screwed up.

Good luck and welcome to GM's answer to the question "How to put a big thingy into small thingy?".

[merc81]

Just a side bar correction. The thing in the back behind and below the coil pack with two vacuum lines is the EVAP solonoid. One of the vacuum lines goes up to the manifold vacuum, the other goes up to a quick disconnect with pressure test fitting near the fuel lines and then finds its way down to the purge cannister under the car by the fuel tank.
The MAP sensor is the flat pack in front of the coils (and to the right a bit) that is held by a metal bracket mounted on one of the upper manifold screws. It has one vacuum line (part of a tee fitting) and a 3 pin connector going to it.

John

[cfrank2]

Lisle tool company makes a tool just for gm front wheel drive vans and cars that tilts the engine foward, there are two support connecting the radiator to the radiator valence, they are called dog bones. To use the tool you remove one dog bone and bolt in the tool in its place and remove and set aside the other dog bone. This tool lets you tilt the engine and it holds it in place while you work. I used one on my 1997 chevy lumina to change spark plugs and it worked VERY well. You dont need to disconnect anything either you should just make sure you dont tilt it too far foward and damage somehting. Here is a link to it: http://www.cartools.com/Merchant2/me...tegory_Code=EG