If you don't feel like reading a novel the questions are at the bottom.



If you asked me the one thing I need in life, it would be a car that I love. Unless my girlfriend is in the room. I've had some worth loving over the years. A minty two tone paint El Camino. A dead simple regular cab F150. (Both bench seats, both great on dates) A Suzuki Sidekick that just wouldn't die, even when the body would jump up and bang back onto the frame when it drove over a speed bump. I swear all that was holding that car together was the steering column.

Fast forward to now, I've had a string of boring cars. Cars you would consider to be 'economical' and 'reasonable' for a poor student. A Chevrolet HHR, notice how I had to say Chevrolet first? HHR alone doesn't ring many bells, and for good reason. Or my simple little Honda now. Yawn. You know what car I liked? One car I never will forget? My Dad's 1984 Volvo 760 Turbo. That car is burned into my memory. The solid feel of it. Everything in that car felt right. It always had enough power, it was always comfortable. It was no sports car but it never left you wondering how it would behave in a corner. You knew, solid. It's that car and my memories of Dad that were on my mind when I took home a black on black 1994 Volvo 850 Turbo Wagon last week.

I'm not sure if it's an 'economical' or a 'reasonable' car, but the price was right, $500. It has a misfire. The red blinking light under the hood says it has 2 an open circuits in the climate control, which may be the reason the last owner says the battery kept going dead. The a/c compressor seems to have a drinking problem because it is sitting at the bottom of the engine covered in it's own liquids. But most importantly is the engine has a constant misfire and it doesn't seem to know which of it's cylinders to blame. All it tells me is there is low input (or output?) from the ETM. Maybe this is a bad ground, or maybe the sensor and associated resistance strips have wiped themselves clean. Now if only the a/c compressor would do that.

The real problem though seems to lay in the heart of this neglected machine. When I drained the oil I was convinced the swedes located the fuel tank directly under the engine. What a silly thing to do. Or could it be that this car has been misfiring for so long that that oil has been replaced with fuel? So with that...

Cold dry compression test on all 5 cylinders read between 100 - 115 psi. Pour a little oil in and it shoots up over 200 psi. Warm the car up and it wasn't too much different from cold. I called the local Volvo guy about a rebuild and he said I'm better off with a used engine. Says he has one out of an 850R. The 850R is a manual transmission though. Is this a going to work? He said the compression test on my engine, albeit the numbers aren't high they are all even and don't sound that bad to him. I'm thinking the worst for this engine though. He says he has a mechanic who has been with him since the 1960's and he will ask him on Monday when he's back from vacation, assuming he returns.



So the questions are this

With compression around 105 - 115 psi is this engine worth saving?

Can an 850R engine from a manual trans car drop into my 850 Turbo automatic car? (I want to keep my automatic trans.)

Any parts (computers) that I should either keep from my engine or need to come with the 850R manual trans engine?

If I replace with the used engine, what questions should I ask before buying it?



Thanks in advance for any replies. The rest of the car seems to be in pretty good shape. Very minimal rust and decent walnut trim interior.

Shawn

 

My thoughts? Is the engine worth saving? Depends if you want a project with pulling the head etc. I'd probably opt for the swap route - the head from the old engine is probably in good enough shape to sell (lots of 850Ts hit the yards when their timing belt fails and wipes out the exhaust valves) to recover some costs.

The engine from a manual should bolt right in. I'd keep all the bits you can from the 850R. Things to look for are the turbo (then again you may opt for an upgrade to a 16T while the engine is out), starter, alternator. Normally I'd suggest the PCV but your 94 uses the old smaller style and I'm betting the R is newer than engine# 330xxx.

Buying a used engine? Is it currently in the car running? Can you get a compression test on the new engine? Look in the filler cap - any gunk or just staining? Was it running synthetic? total mileage?

 

Talked to him today. He really wants his tech to look at this engine before replacing it. Told me I can make a list of all the things I've observed with it and he will give the list to his tech. I noticed one odd thing today. The cam lobes look perfect. If diluted oil caused the piston rings to wear prematurely wouldn't the cam lobes be worn too?

Shawn

 

who did the compression test? I'm thinking along the lines of "second opinion" here. Does the engine show any issues other than the misfire like a long initial crank on a cold start (a sign of low compression)? Rings can wear different ways - cylinder walls can score, rings can get "tired" (lose tension) - your oil rings and compression rings can wear at different rates or get some crud in the rings etc. I'd try throwing a heavier oil in for the summer (I used to own a series of BMW 2002s and it was a common practice to run 20/50 in the summer and 10/40 in the winter) and consider a detergent treatment like Seafoam before pulling the plug on an engine swap. I'm not sure if I'd assume directly that the misfire is due to compression. the fact you noted 110 across the board suggests the measuring was off not the compression.

 

I am curious about the crankcase being full of gasoline. Are you sure? What did you observe?

 

The crank case wasn't actually full of gasoline, but the oil looked to be heavily diluted. I'm assuming this is due to some random misfire that I am yet to diagnose.

Tonight I did the compression test again. Cold/dry numbers where all around 120 psi. Cold/wet numbers where all between 145-165, probably fluctuated just because I didn't add enough oil to some.

I fired it up and it was misfiring and making clacking/knocking noises. I messed around the plug wires for a while and eventually, maybe by co-incidence it stopped misfiring and quieted down. Then I took it for a ride. And I'll tell you what, even if this engine is worn out, and is way down on compression, I drove around for a bit and then I put my foot into it, and that car got up and went. At this point I think as far as I'm concerned that car has enough power for me. I would love to know what the engine is like with good compression, and yes it will bug the hell out of me and probably keep me up some nights. But whatever, life is short and I'm going to drive the damn thing and that's it. I hope.

That said there are a whole bunch of little things the car needs. But truth be told, I think I bought it because I missed tinkering on a car I actually gave a **** about, instead of fixing cars I didn't. So, I got what I bargained for. Time will tell.

Shawn

 

They tend to make a lot of valvetrain noise when they've been sitting, and my experience has always been in about 15 minutes the lash adjusters will pump up. So maybe you've fixed that problem. Glad to hear it's not missing.


As far as power bone stock with good compression, I don't suppose that is easy to describe apart from actual acceleration numbers. They are plenty fast.

 

Ok, next question.

How many engine / transmission mounts are there?

Where are they?

What are their names, so I order the right ones. Pretty sure they may need replacing, the one torque mount atop the engine has disintegrated.

Also

If the rear end is thunking over bumps, what is the likely culprit?

Thanks
Shawn

 

There is an upper and lower torque strut mount. You also have a lower mount on the front passenger side, and 2 (3?) fluid filled mounts (one above the middle of the steering rack, one on the front driver side, and if I remember correctly 1 more that I can't seem to place at the moment.) For the torque strut mounts, you can get polyurethane replacements either in the full mount or inserts for the factory mount. ipdUSA is a good place to look for them. There are also 4 subframe mounts that you may want to consider replacing. IPD makes poly inserts for these as well.

As for the rear end clunk over bumps, it could be worn struts, worn spring seats, rear lateral links...anything really. My money is on spring seats though, these cars are known to clunk when they are worn (my 97 that I had started in the right front just after replacing the control arm).

 

The spring seats in the back are quite a lot different from the front, and I don't think they'd clunk. At least if they did, it wouldn't be the same reason they make noise on the front.

 

Only other real suggestion I have is maybe worn bump stops or spring seat insulators...Not sure on the latter, haven't really gotten into the rear suspension on these cars too much yet...

 

Right on guys, thanks. I'm checking them out right now to see what needs replacing.

I need to do the timing belt because I don't know when or if it's been done. I'm on a budget so which of the parts of this kit should I consider essential to replace?
Volvo Engine Timing Belt Kit - 102K10063 - Free Shipping Available

Thanks again, I appreciate the help. Taking the fear out of owning a European car. Come to think of it, this is my first.
Shawn

 

regarding the timing belt: remove the 12mm holding on the timing belt cover. If the cover and interior is clean and dry you can do the simple kit: Belt, Idler, tensioner. You need to pull off the serpentine for access so that's a good time to feel the idlers and pony up the $15 for a new drive belt. If you see any oil leaks - ie cam seals, crank seal, this is the time to do them. If you see coolant, time to do the water pump.

 

Thanks bud, that's perfect.

 

Question about the rear suspension. How do I diagnose what the problem is for each of those things you mentioned? Surprisingly I've never had to replace a rear suspension component on any car I've owned so I'm a little green around those parts.

 

the parts that can wear in the rear are the shocks, shock mounts (easy enough to look at), the sway bar end link and bushings and then there's a part called a delta link (kinda like a control arm). I had a shop do the delta links on my 850 wagon as I was told it requires a tool to press in/out