1991 Chinook Aerostar. I'm looking for help with engine parts.

Hi Aerostar/Explorer/Ranger community.

Although this is my first post, I've been reading here since purchasing a '91 XL with a rare OEM Chinook pop-top at the end of Spring 15. I'd never noticed a Chinook minivan on the road, although I'm tuned into pop-top campers. In another century, I suffered thru 4 engine failures on an air-cooled '81 Vanagon Westfalia, the best vehicle I ever rested in after a breakdown.

My current project looked promising; relatively clean body and paint, and only 55K on a 2001 dealership longblock;165K total chassis miles. There were warning signs; a recent water pump replacement, and strangely intermittent white tailpipe smoke. However the mystery smoke didn't prevent it from passing CA smog, even though I could see it during the high RPM test.

I'd fallen for her, and she needed me... the oldest story in a 12-step group. Codependency happens, and history ignored tends to repeat.

It's a moot point whether a weak head gasket led to cracked heads, or if the prior waterpump problem wasn't caught in time. Mea culpa. Shortly after purchase, my '91 boiled dry while a friend was driving it. Thank god for premier AAA membership, someone to call for help. Curse you Ford, for truck with a dummy light, instead of a temp gauge.

Fast-forward to late July 2015; my mechanic has the pushrod/OHV engine out on a stand. I'm shopping for a long list of expensive parts while we're waiting for new heads from Cylinder Heads International, headsonly.com. That's a fact, not a recommendation- but Chris, the man on the phone seemed helpful, and the price was right.

Since I'm busy trying to work the cost-quality-longevity curve on a big parts/labor bill, that's all of my sad (so far) story that I've time to tell, for now. I'll come back when I have a happy ending, or at least get back to re-imagining a camper interior.

I will ask if anyone reading this about Evergreen Performance engine gasket kit experience. And whether the roller valve lifters are difficult to recondition. Lifters and Fel-Pro gaskets are the biggest line items on the engine list.

Welcome to the forum

I moved your thread to our Aerostar subforum.

Welcome to this forum! How many miles does the 1991 Aerostar have? Could you post a picture of the top which you're referring to?

91 Chinook Aerostar revival

Thx for bringing my post to the right place Rick!

BBay, Odometer shows 166K: The shoebox of paperwork that came with shows a dealership longblock was installed at 111K, in 2001. Taking the arithmetic at face value, there was 55K on the engine, when it lost coolant and cracked the heads.

(A proper temp gauge is on my refit list, if anyone has an aftermarket suggestion; I presume the sender generates an analog signal for the ECM/PCM management.)

I've got pics of the OEM Chinook top, both up and down. But I haven't noodled out where the photo import dialogue for this forum starts. Drag n drop aor clipboard copy from my steam powered macbook isn't getting them in here.

BTW I could use a belly-up van icon... for now

91 Aerostar Chinook pop-top pics.

OK, I popped for the membership, lets see if the attachments do.

There should be 2 pics here, one with the Chinook-aerostar top down, and one with it extended (should be tighter), giving about 6'6" standup room. My unit didn't have anything inside in the way of camping equipment, other than an AC input on the driver-rear exterior, and an AC output behind the rear seat. There was a worn out bed that extended from under the heavy wayback seat that I recycled. I understand there was originally a removeable DC cooler, similar to the Vanagon Weekender poptop.

It's a good looking, durable fiberglass top, I think, what you'd expect from the Chinook folks. It's raised by springs on scissor lifters, on front and sides. Not much weathering after nearly 20 years even the canvas sides are still in pretty good shape. the scissor attachments at the raised fiberglass roof gasket need rework, probably threaded inserts, where screws go into the fiberglass

If you look up Chinook on Wikipedia, you'll learn that they tried to get something going with several US companies, after Toyota withdrew support on the Hilux flatbed platform, around 1980.

Chinook correction

OK, I lied; you can see that the third scissor support is in the rear.

Also, this is the E-4WD version of Aerostar. I got 19mpg before the meltdown, which is pretty good for the size and weight.

I'm planning an Xmas-NYear trip from SoCal out to visit family in Colorado Springs. The AWD may come in handy, across the Divide and the re-freeze zones.

i had no idea these were made.3.0 or 4.0?

Thanks for getting an elite membership! This is the first time that I've seen an automatic pop top . Could you take a picture of it from the inside? According to what you've written until now, you're saying that this was OEM (ordered from the dealership brand new with this top)? This wasn't something that was added later on by a specialty shop? I have Ford manuals, CDs, DVD's, Haynes, Chilton, and Clymer, and never came across this.

91 4.0l e-4wd chinook pop-top

I posted a wordy reply last night, but the dog seems to have et my homework

Chinook top is spring assisted, not automatic. You can see one of the vinyl sleeved springs in the pic, masquerading as a pneumatic lifter. The internal clips and velcro have to be manipulated before pushing it up. There are OEM planks to make up a kids bed at roof level, but no upstairs sleeper a la Westfalia vanagon.

I'll check the shoebox for the original Ford sales receipt. If you look at Chinook/wiki writeup, you'll see where they experimented with several US light truck conversions, including GM, as they phased out of their 1/2 ton HiLux flatbed era of the 70's.

The Aero history here tells me that the E4WD models were all 4.0L. The poptop adds more weight, and any camper gear even more. So the upsize engine makes sense. I think my curb weight is 5,500, fairly evenly split between the axles.

Thx for the interest in the feature that makes this van worth repairing, but I really do need mechanical/parts help, to keep costs on an extensive list of repairs under control.

I've posted an initial query at the link below: hope it's in the right place.
Troubleshooting - Modifications & Detailing Forums > Elite Explorer 911!

'91 4.0 OHV lifter/pushrod questions
http://www.explorerforum.com/forums/showthread.php?t=431159

5500 lb curb weight is extremely impressive. My 91 extended van is around 3600. I put 250 sq/ft granite stone tile in the back which was about 1800 lbs. That put my van around 5400 lbs, I couldn't put my hand under the running board it was that low to the ground. I popped 3 tires that were extra load rated.

Today I found what I believe to be this aerostar for sale on craigslist. I'd buy it at that price but I have way too many projects now.

http://sandiego.craigslist.org/ssd/cto/5424278833.html

You could install a V8 in there since the engine is already out. It would be even more interesting if you installed an electric motor instead of a gasoline powered engine.

Diesel would be cool too.

I was thinking of a hybrid conversion, putting in batteries and an electric motor in place of the front driveshaft.

The E4WD front driveline does complicate the stock 2wd power steering. The front differential displaces the frame crossmember, so it boxes the steering rack. My leaking rack can only be removed/replaced with a major dissassembly of the lower swingarms and springs. A shop estimate was $1400.

Very interesting thread! I had never seen one. Gas mileage is probably pretty bad,but hey,whatever floats yer boat! don-ohio ^)

Did you ever try Lucas for power steering?

Yes, the Lucas slowed the p.steering rack leak down quite a bit. It was getting 18-19 mpg fwy (with adequate power), until a leaky radiator/coolant loss (and an inattentive driver) killed the 4.0engine.

Post mortem showed a lotta wear on both ends of the rockers, and on the push rod ends, with less than 60K on a dealer long-block. Apparently Ford V6 lubrication is an issue, given weak metal in the OEM Ford rockers. The folks at Delta Camshaft sold me rocker assemblies with hardened insert cups for the push rods, and hardened faces against the valve stems.

A rebuilt engine is expensive, but did you look into a used engine from a junkyard?

I think the Ranger/Explorer community sucks up used engines and parts pretty quickly, as they become avail. We did look for one, and maybe weren't patient enough. New 91-94 4.0 heads are affordable, $475 shipped. Those double-wall roller-lifter interior chambers are impossible to get completely carbon free and pricey to replace; $25-50 ea. X 12, more than the new heads from Heads Only.

I'm told the Ford OEM rockers are soft steel, prone to wear fast and leach oil pressure. At 50K, all mine had valve stem dents, and worn-open oil ports on the pushrod end. Thanks for negative customer respect on that, Detroit. I'd be running synthetic and/or diesel oil in that vintage 4.0, knowing what I know now, to stretch the rocker/pushrod/lifter/cam lifecycle.

Here in Phoenix they are easy to find. I see awd Aerostar vans in the yards too. Might be worth a trip.