Hi everyone, I'm new to the Volvo community and would love any help you could offer.

I purchased a 1994 850 Turbo last year with about 80K miles on it. Unbeknownst to me (and certainly my bad for not checking), the timing belt had never been changed.

Last week it snapped.

So I talked to my mechanic who said that despite this car having an interference engine, he's worked on 2 Volvos (similar years) that blew their timing belt and when he replaced the belt, low and behold, they fired right up. His suggestion was to spend the $23 for a belt and give it a try.

So I went through the entire process of installing the new timing belt. I made sure the marks lined up on both the intake and exhaust cams as well as the crank.

When I go to start the car though - it doesn't turn over. In fact, other than all the wheels that the belt runs over spinning, it does nothing. No firing, no noise - just the whir of the wheels spinning around.

So my question is this: I noticed that for every turn of the crank, the cams turn twice. Is it possible that one or the other, or both, of the cam wheels need to be turned exactly 360 degrees to fix the problem? My mechanic said that it's possible that the valves are open when cylinder 1 is at TDC and that's why it's not firing - because the cams are exactly 1 full turn off. Is this making sense? Is there any truth to this?

The walkthroughs I went through to do the belt assumed that I was pulling off an old belt and that those marks wouldn't be moving much during the change (certainly not a full turn) but in my case, who knows how many times each of those wheels spun around when the belt snapped.

Or am I overthinking this and if all 3 marks line up and the car doesn't start it's just plain dead? I would have thought that if the valves were messed up I'd at least hear something that sounded like the engine trying to do something but no - just those wheels spinning around - no activity at the top of the engine whatsoever.

Someone else suggested that maybe the timing is just off because the old belt had stretched out. I'm not a mechanic - I don't know how these things work...

The suggestion to figure out if valves may be open was to make sure cylinder 1 is at TDC by putting a screwdriver in socket 1 and spinning the crank until it's at full height - (I'm assuming it should be at TDC if the crank is on the timing mark - is this right?) - and then doing a leakdown test on that cylinder to see if air is blowing out either the intake or exhaust end - and whichever end is leaking, spin that wheel exactly 360 degrees back to the timing mark. In theory, if the valves aren't toast, then I shouldn't have air leaking through if everything is lined up correctly - yeah?

I'm hoping this car isn't completely toast but you'll know better than me.

Any thoughts? Suggestions?

I appreciate your consideration!

- Ethan

 

The valves are open... because they are bent. Sorry.

 

First, let me say "I think I know what you mean" about cranking the engine, and the sound is just a whir, but the engine is turning sort of normally. I have experienced that. It is caused by not having compression on any cylinder. In your case, this might make sense.

Second, lots of people are curious about whether the cams or crank need to be turned 360 degrees, or in the case of the old V8's, they'd want to turn the one cam 180. This does not make sense. It's wrong. People do struggle with it mentaly all the time. If somebody tells you it makes sense, don't listen. What makes sense is to get those three shafts in time.

My 850's don't have timing marks, so I am a skeptic when it comes to timing something with a broken belt. You might consider timing it using the other indications. They are correctly timed using a crank blocking device and a tool that runs through some slots on the back end of the cams. However, the chance of this being all okay at the end is not very good.

 

I'm skeptical of people who say they have no timing marks.

 

might as well pull the head and fix it

 

Anyone have a ballpark idea of what I'm looking at for repairs? Should I just sell the car as a hunk-o-metal and start looking for a new vehicle? I'm in Hawaii so shipping a new engine here is out of the question. I'm somewhat mechanically inclined and I have a fair bit of tools but I'm also not into taking on a million-hour project or dropping thousands of dollars on this car. Damn shame - it's in great condition... other than the fact that it no longer runs...

 

You could investigate the price (with shipping) of a rebuilt head and go from there.

 

call my friend Matt Hodges in Honolulu at Autoworks - Great guy!
Tell him Tim sent you!

 

Yeah, a rebuilt head would most likely be the cheapest option. It would probably be less than buying all the valves, and then you'd still need machine work.

Of course, add in the other parts you need (head gasket, intake gasket, exhaust gasket, thermostat housing gasket, water pipe gasket, cam seals, spark plug well o-rings, timing belt kit, head bolts) and the parts you don't need but might as well replace while it's all apart (thermostat, spark plugs, water pump, possibly plug wires)

 

Don't forget Volvo anaerobic sealant.

 

Swapping a head is a big job, but it's doable if you are mechanically inclined.

Don't forget the new head bolts. The originals aren't reusable.

http://www.matthewsvolvosite.com/how...volvo-850.html

While it's apart, consider changing the 8 coolant hoses and the PCV system. Everything is easier to get to without a head installed.

 

Well, now you have answers from two Volvo forums all saying you need to pull the head. Whats your plan?

 

I have swapped several heads on the 850. Yes, it is a rather involved job, but it is definitely do-able, especially if the rest of the car is save-able. I would say you are looking at between 700 to 1500 dollars if you get a good used head and replace all the required parts (timing belt, tensioner, all idler pulleys, water pump, serpentine belt, head gasket, head bolts, intake and exhaust gaskets). But once that is all done you are good for another 80,000 miles or so, and on Hawaii that will be MANY years down the road.

 

Got to thinking a bit more about this...

You need A GOOD 1/2 inch drive 14mm deep socket.

Maybe have *2* of them.

The first 850 head I pulled, I did several in, just removing the head from the donor car to take to the machine shop.

1/2 drive breaker bar with a cheater bar (piece of pipe to slide over the end of the breaker bar) will be necessary to pull those head bolts if you are doing it with hand tools. They are REALLY tight.

Also, lots of good stuff on Robert's YouTube channel:

 

timing marks are there. cams are easy to see, crank timing mark is hard to see from the wheel well - best seen with the belt off (on the block side of the pulley, aligns to the oil pump edge). For used heads I'd search yards via car-parts.com or find a Craigslist car where the engine is running (ie don't want a head from a car with a blown head gasket as it may be cracked or warped). Have a machine shop measure for flatness and inspect for possible cracks (ie magnaflux test) can save you a bit headache later.

 

Hi everyone - thanks so much for all your feedback. *I'm not sure what I'll do yet. *I'll plan to do a compression test this week but I think we all know what the verdict is. *I really appreciate everyone's input - you guys rock! *I'll be sure to post what I end up doing with this situation.

Thanks again.

Forum contributors are the unsung heroes of our day! *Cheers to you all!