Removing internal thermostat without dropping engine

[jwakil]

I have an 83SC with 77 3.0 carrara engine (with CIS). I need to check my internal oil cooler thermostat and don't really have a car lift, transmission jack and helper to help me drop the engine, so I was thinking of taking out the CIS and intake pipes to get access to the front of the engine. I know most people say it's easier dropping the engine, but in my situation how much work is involved in taking out all the stuff on top of the engine and would still have to drop the engine to get some of the components out? It seems to me there is enough clearance to take all the CIS out as a unit if I take the rubber boots off, but I haven't tried.

[onboost]

You don't have to remove the injection to do this. Simply lower the engine down on with a floor jack and have at it.

You may have to disconnect various harness connections, hoses, and possibly lower the sway bar for some extra clearance based on how far you need to lower.

I would also spray the area with some carb cleaner and wipe down to ensure that no grease, dirt, or other debris fall into the thermostat cavity when you pull it out.

I've done it this way many times over the years to replace thermostat seal and leaking oil sending unit... etc.

Good luck..

[sparkle84]

There's a lot more involved than just removing the rubber sleeves. If you just drop the engine down 4-5" & remove the sensor plate boot you should have room to get at it. Will need to remove some hoses, brackets, etc. but it's doable. Buy a cheap floor jack at Autozone (20.00), disconnect the rear crossmember bolts & the shift rod behind the cover on the rear floor & you're good to go. Can easily lower the engine 4-5' without disconnecting anything else. Much easier than removing the whole CIS. Of course removing the CIS would allow you to take care of anything else that needs doing but will turn it into a week long project instead of a 1 day project. If you go that route might as well replace every sleeve, gasket, vac line & O-ring there (approx. 150.00 in parts). Clean everything,etc. You'll now run the risk of joining the legions of people who've refurbished they're CIS & then have CIS problems that didn't exist prior. If car runs well I'd just go the small drop routine. If so replace the oil switch while there. Nice to do the breather cover gasket also but that's a ***** with the engine in. Check out the Tech articles "fixing oil leaks & partial engine drop" to get an idea what's involved. This procedure isn't really hard per se but can be pretty frustrating.

Good Luck

[john walker's workshop]

in reality, you really should just remove the engine, unless you're pretzyl man. don't forget to disconnect the shift coupler, whether you just drop it or remove it.

[jwakil]

I'm afraid the engine might tip over on the floor jack if it is not weight balanced, which was why I was avoiding dropping the engine without a helper. Where do I put the jack to make sure that the engine can be lowered straight down without rocking off.

[john walker's workshop]

buy a 3'8" thick square plate, big enough to span the heat exchangers and bolt it to your jack pad. then measure the distance between the rearmost holes on the exchangers and transfer that to the plate. drill holes and run two 3" bolts up from underneath and secure with a nut. raise up under the engine so the bolts enter the exchanger holes.

[Superman]

Or just do what I do. Let it fall off the floor jack, then figure out a way to get the jack under it again. My projects are not as boring as you guys'.

[jwakil]

I tried doing the partial engine drop (lowered back end at least six inches) and removed the rubber boot on the intake, but it still seemed impossible to get to the thermostat, or remove the hoses above it. It seemed the only solution would be to drop both the transmission and engine close to a foot. If I go straight down ~10 inches, would I still need to disconnect the CV joints and clutch cable? Since I don't have a helper, I thought keeping the CV joints attached would provide some safegaurds against the whole thing rocking off the jack (left and right) and if I can keep the clutch cable attached that would minimize the work involved.

[Walt Fricke]

Don't keep the clutch cable attached if you plan to remove the two large transmission bolts. It is not designed to act as a tether. And pull the accelerator linkage from the transmission bell crank as well if you are going to do this.

You do know that you will end up with the engine/transmission unit supported on the front end by the transmission shift rod, which will still be sticking into its hole in the chassis. We are advised not to put weight on this part, which was not designed for weight bearing. Though I often do have some of the weight of the assembly on it when R&Ring the power train as a unit, without ill effect. But not much, and not for long. This is going to limit your gain in working space. You have to move the assembly so far to the rear to get this rod clear that the alternator will bump into the cross member. To deal with that, you have to have the rear of the car way way up on jack stands, and tilt the unit way down. Which is standard for removing the whole thing, but you can't get close to this with the CVs still attached.

I suppose you can get a few more inches of overhead clearance by removing the transmission bolts. But then you will be faced with the often daunting task of getting those two long bolts back into their threaded holes without stripping the threads. All by yourself, with the engine perched on one jack while you are on your back under the car.

I do this all the time when reinstalling my transmission, so I have faith that nothing is going to squash me. But you don't.

I recommend you do a partial drop, leaving the transmission bolts alone, and see if you can get to the thermostat. You can see what is going on, you are safely out of the way, You can micro-adjust your jack without having to crawl out from under the car, then back under, etc. Much less fretting.

I do have a sort of vested interest in the efficacy of the partial drop, I must disclose. And I used it with great success to get at the idiot light sender on a 2.7. I never did it on a 3.2.

Walt

[jwakil]

Thanks for the good pointers. I've always wondered about the load on the shift rod when tilting the engine/transmission enough to pull them out. I didn't think that it might be worse if I went straight down. Wouldn't that thing bend/break when you tilt down enough to clear everything? How far can I bend down on the partial drop without damaging CVs or shift rod? I was afraid to go more than six inches. I can disconnect the CVs if needed but would rather avoid.

[efhughes3]

I'm a fan of engine-only drops, and in this case would probably pay dividends in time saved. Some say it is hard to get the clutch fork over the throwout bearing, but I've not experienced that. Plus, you get to leave the CV's alone.

[Walt Fricke]

Unless you abuse things, disconnecting the shift coupler back at the rear of the tunnel inside that car will pretty much keep you from doing damage there. (do this by loosening the Allen grub screw on the rear of the coupler, not the clamp part in the front, so it will be in the exact same position when you reinstall it after you are done).

If you leave the transmission mounts in, you won't damage the transmission shift rod because it won't be taking weight, and there won't be anything trying to hold it on its front end once the coupler is disconnected.

If you try to lower farther, by taking out the transmission bolts, as long as you keep some support under the transmission you shouldn't damage it either. But I wouldn't even try this stuff without one good floor jack under the rear of the engine, and another farther forward under the transmission. This isn't like pulling the engine/tranny as a unit.

You really have to be careful about various umbilicals no matter how you do it The big rubber S hose from the oil tank isn't going to let you get too low. And you can't really pull the engine backward much with this line attached. It isn't made to compress. So you'd have to drain all the oil, as in an oil change. There are other lines - the breather hose, the fuel lines in particular. And the wiring, though much of that is covered by the big 14 pin plug. And then there are the two short hoses which connect the heat exchangers to the chassis of the car. They will stretch a little, but not really more than a "standard" partial drop will allow.

You ain't seen nothing yet until you try to reattach these short hoses with the engine all bolted into the chassis.

Can you see why several on this list are trying to discourage you from doing more than the "partial drop?" Of course, we've all pulled engines/trannies as a unit, and aren't afraid of it (though we all calculate the relative labor of one or the other method of getting at something).

Walt

[Walt Fricke]

I, too, like the engine only mode. However, on my track car I have easy access to the top of the transmission (which has solid mounts) and hook a chain to it and to some roll cage stuff to hold the tranny up. I've modified the rear cross member so I can get the alternator (but not, alas, the carbs) through it, which means I can then drop the engine to a dolly because the tranny input shaft is clear, and pull it out backward. A bit harder to do all this with a separate jack under the tranny in a normal street car, though I think not too much. The engine balances on the sump plate (or where it would be on later cases).

Sometimes I get the clutch fork engaged right first try. Sometimes only after many tries and a lot of cursing. High on the improvement list for the track car is a 5.5" "push" clutch, so nothing has to be engaged. I can usually pull or install its engine in under an hour, and am always looking for ways to cut that down even more.

[jwakil]

I've already done all the disconnects of the shifter rod, oil lines, the short fuel lines, and engine harness, so those are not the issue. My question was, if I lower the back end ~1 foot, with the transmissiion mounts still bolted and CVs and clutch cable still attached, is everything going to be OK or will I bend/break something? Is there enough room for the shift rod to swing up and not get bent in the chasis, and will transmission mounts and CV joints bend that much?

[Walt Fricke]

Naw, the shift rod has plenty of room to swing. Since I've always had some of that stuff still attached, I don't know how far you can go with the axles in place. The CVs have maybe around an inch of in and out, so if they start centered, you have an inch of effective axle elongation per side. You can't hurt them, though I'd not be inclined to try to support the whole shebang from them.

If you don't put the rear up on jack stands, I think your lower limit will be the thickness of your jack when fully retracted.

I've seen a rear motor mount fail, with parts of the motor dragging on the track for a lap. New mount, back in business for the next race. The rubber transmission mounts have a lot of compliance.

I once unbolted the rear mount, and left things for the morning, with the jack supporting the rear of the engine. The jack slowly lowered over the night. Oh, oh. But no damage.

The $64 question is whether you will gain enough working room over the engine. For which you probably don't want the rear of the car way up in the air anyway.

[jwakil]

Thanks, that gives me more confidence to try to lower further. Last time I only went ~6-8inches on the rear drop. This time I'm going to go down about a foot. I think that should give me enough room to at least not have to squeeze my head above the CIS. Hopefully I can get away with this without the full drop. I Well let you know how it turns out next week.

[john walker's workshop]

be sure to disconnect the shift coupler. lower it until the fan housing just clears the rear cross-member. that's about the end of the safe/won't bend anything range. that's where it needs to be if you remove the engine and leave the trans in place, if you were to do that.

[jwakil]

Success. Thanks for the pointers. I was able to get away with a partial drop by going down close to a foot and got that thermostat out That saved me a lot of work. And sure enough, I believe I have a faulty thermostat. I dropped it in some boiling water and it didn't open at all. Which brings me to a couple of more questions:
1. Some places I've read that the internal TSTAT is supposed to open at ~180F, but I thought I remember reading ~240F as well. Is it 180 for sure?

2. The other thing is, when I get my new thermostat I was going to do the boiling water test. Will the water cause any damage or rusting of the key components? Is it safe to do on a new thermostat?

[dshepp806]

I would think the 180 degrees is correct.

Doyle

[Walt Fricke]

Bravo

About 90 degrees C.

If it is brand new, I'd be inclined to put it in.

If used, I'd test.

Though I think the one I tested which worked went on to do the job.

It isn't going to rust: it won't be in the water long, the water will get dried off and evaporate anyway, and it will soon be bathed in oil for the rest of its unnatural life.