All of a sudden she started making this loud knocking/tapping

shadetree_v70 · Post by **shadetree_v70** » 26 Feb 2018, 08:52

UPDATE: Determined to be knocking rod. My wife's co-worker's dad is a Volvo master mechanic, he came over to put an ear on things and that was his determination. Something I never did was to pull injectors one at a time to see if the noise lessened, which I believe is how he came to that conclusion. So, the past week was looking for a motor, found one with 81000 miles and turbo included (I hope that's true) and if it arrives in time I'll be installing it this weekend. I did have the sense to order Axle seals, front and rear main seals, oil sump kit, motor mounts, and all the o-rings to replace while its out of the car and easy to do. This week will be about pulling the old motor and degreasing/power washing 330,000 miles of built-up "character". Oh, and Ill be doing the subframe bushings for good measure.

Post by **erikv11** » 26 Feb 2018, 09:04

Sounds like you are well on your way, good choice of items to fix while the engine is out. I also swapped in a rebuilt steering rack on my last engine job - so much easier when the engine it out. Consider adding a timing belt job to the replacement engine, and this is a convenient opportunity to replace the lower radiator hose with a quality Volvo part and never have to think about that one again. Front main seal you could probably pass on, those are so, so rare to fail.

Is the replacement engine a T5 or the same low pressure turbo?

shadetree_v70 · Post by **shadetree_v70** » 26 Feb 2018, 09:48

Timing belt/water pump, and related bits are <8000mi old, and lower rad hose is even more recent. I had the same thought about front crank seal but while it's so easy to access, why tempt Murphy? I may even properly gap the A/C clutch and get the rid of the zipties!

Does anyone know bolt dimensions to mount the engine on a stand? Also, where are the preferred attach points for the hoist chain? The hoist I'm borrowing does have a leveler, so that's awesome.

Post by **June** » 26 Feb 2018, 09:50

Don't forget those small coolant hose pieces going to the turbo. I understand those are hard to replace in vehicle and should be replaced with OEM hose. June

shadetree_v70 · Post by **shadetree_v70** » 26 Feb 2018, 11:03

Thank you! I had just replaced that pesky elbow one before this started.

Oly850 · Post by **Oly850** » 05 Mar 2018, 21:28

This sounds like a collapsed / stuck lifter. It's a high tinny knock that's tied to RPM. If it was electrical / ignition it wouldn't be this uniform. These hydraulic lifters rotate in their bores during operation and I think you'll find one is stuck in it's bore. It's a job I'm afraid, and the lifter bores are intergral to the head, no liners, and the lifter is steel. As this may not be repairable, (might need a new head) it won't hurt to take it apart. I wouldn't drive it.

Post by **JimBee** » 09 Mar 2018, 21:01

If the new engine has been well maintained, the lower end should be fine. But you never know unless you look. You're going to have the pan off anyway, might as well pull the bearing caps to check for any burnishing, copper-looking streaks or any markings other than smooth gray surfaces. With the engine on its side you can have the caps on and off in an hour (replaced with a light smear of reassembly grease). Just for peace of mind.

I would also check rod straightness, again pretty easy with good light and the engine on its side. One easy way to do that is measure the clearance between the crankshaft counterweights (which will be at the top when the pistons are at BDC) and the corresponding bottoms of the piston skirts.

With the pistons at TDC, you can also check that the lower cylinder walls are nice and smooth.

If all is good, with other updates you're planning, you should have a brand new engine!

+++++
I just read the rest of your post.
I'm betting you have a bent connecting rod that's making the clinking noise. How did that happen? Gawd only knows. I've had one. I too hoped it was a lifter, but I had them all checked and it wasn't that. It sounded just like yours. While you have the original engine out, pull the pan and check the clearances between the counterweight and piston skirt like I suggested above. The metallic knocking sound is likely coming from the contact of one of your crankshaft counterweights and a piston skirt. They normally run really close together, so it doesn't take much of a bend for the contact to happen.

My engine otherwise was fine. All the bearing surfaces were excellent and the crank journals were mirror finish. I showed the bearing inserts to 3 rebuilders and they all said they would reuse them. My engine had upwards of 200k miles on it. I replaced the rod several years ago and although I don't put high miles on that car, it has been running fine.

I found a used connecting rod here:
http://crankshaftsupply.com/

I wrote up the rebuild here, includes a photo of the bent rod near the end:
viewtopic.php?t=75068

shadetree_v70 · Post by **shadetree_v70** » 19 Mar 2018, 19:11

UPDATE: I found a motor from a 97 850 a couple weeks on eBay with 81k. The best part was that it came with the turbo and all of the accessories still bolted on! The old motor is out, subframe bushings done, swaybar bushings done, and 20 years of grime (18 in New England) pressure washed and degreased. New motor mounts too. I transferred all the timing parts and alternator over because they are new. I wish I could transfer the a/c compressor but I don’t have a way to evacuate and recharge the system. I’ll have to settle for a re-shim of the old one, still hooked up.

So I was tinkering after work installing axle seals and transferring that pesky elbow coolant hose to the turbo and noticed that the new motor doesn’t have something my old one does: a really thin metal line that is “metal ziptied” to the main coolant tube. There’s a white plastic vac line on the end under the distributed cap. Can I live without it? I don’t think it will survive being removed, it’s pretty crusty.

Post by **oragex** » 20 Mar 2018, 08:16

I'd do the PCV while the engine is out. At 80K miles is about the right time for it.

shadetree_v70 · Post by **shadetree_v70** » 20 Mar 2018, 10:51

As a preventative measure I dropped the oil pan of the "new" motor and did the sump o rings, inspected the breather passage up to the head, clean as a whistle (good sign), didn't see the need to replace the entire pcv system at this point. I can't believe the trap would be full or clogged at this point.

All of a sudden she started making this loud knocking/tapping

Re: All of a sudden she started making this loud knocking/tapping