Hello all!! My mom has a 1994 Volvo 850 non turbo with about 120,000 miles on it. She was complaining that it was running a bit rough didn't have as much pick up as it once did not too long ago. I decided I would take the car for the weekend and give it a good tune up. So here's what I replaced (All Volvo parts)
[ul][*]Ran Seafoam through vacuum, tank and crankcase[*]Oil and filter change (Mobil 1 10w-30)[*]Replace spark plugs[*]Replace spark plug wires[*]Replace Cap and Rotor[*]Cleaned Throttle body[*]Cleaned IACV[*]Replaced air filter[*]Replaced Fuel Filter[/ul]
Here's my questions and please bear with me as I don't have much experience with these cars. When I start the car, it kinda sounds like its giving itself a quick shot of gas, like a quick rev and a little shake,is that normal. Also the rough sounds a little loud like it has a slightly modified exhast or something, just a prominate hum sort fo sound. Also I have to agree with my mom, it doesn't have the zip it once had, kind have to give it a good amount of gas to get it to go. I know its older and the miles are getting up there, but is there anything you guys can suggest I try? I almost forgot to mention, I have new enginemounts coming in next week, are they hard to do and will I notice the difference? One more thing, how do you know that the spark plug wires need to be changed? I heard somewhere there is a date printed on the originals?? Thanks for any and all suggestions!!

 

Yes the originals have a date stamped on them.
Is the check engine light on?
Maybe it has a bad O2 sensor.

 

No check engine light. Do theO2 usually go bad? Is there a way to check them? Thanks for your help!

 

Mine was running rough, turned out to be the air mass meter (AKA MAF sensor). This is located near the airbox and it may just be dirty. In my case it needed to be replaced and while not cheap (£180 new for a bosch one, £60 for a used Bosch one don't bother with an aftermarket one they are rubbish) it's a differant car now that it's changed and the fault codes cleared.

Lambda (o2) sensor is another possibility, ideally you need to get the codes read if the check engine light is on.

120k is nothing, mine's done 178k and there are loads of these that have well over 200k and going strong. When i start mine it has a rev up to about 1.5k and then coems down quite quickly to about 1k.

 

If you had the proper scanner you might be able to read the sweep.

Make sure the check engine light does work in the cluster as well.

Or follow instructions in the link to learn how to pull the codes from the OBDI under the hood.
Check A2 and A6 for codes.
http://www.troublecodes.net/Volvo/

 

Thanks. I pulled the codes are everything is clean and the light does work (it was on a few weeks ago). I will work on getting a replacement O2 sensor, anything else you can recommend that would need checking or replacement (All maintenance has been done ie timing belt, etc..)? Thanks a bunch.

 

Thanks for the reponse Edge, I will look into cleaning the MAF and see if that helps. My RPM's are about the same, does your sound like you gave it some gas when you start it up too? Thanks

 

All the 850's do a little rev when starting. Both of mine do it.
One of mine have 230K and other has 111K.

 

Ok so I did everything I could and its a bit better. One thing I noticed is that when the car is on and sitting idle, i noticed there is a constantticking noise from the motor. My friend once had this on his Isuzu and it was his lifters. Is this noise normal and is there anything that can be done. I checked oil levels and they are fine. Thanks again!

 

Mine does it too and I thought it wasa clicky tappet but apparantly it's the injectors (a tick noise). Nothing to worry about.

Another thing to try is some carb cleaner on the throttle body, and maybe a shot of injector cleaner. If there are no codes I doubt there is anything the matter with it tbh. A bad O2 sensorshould show on the OBD system or certainly on an emmissions test for the MOT if you're subject to one.

Something else that was wrong with mine was ablocked (creased) vacuum hose deep in the bowels on the engine front face. My mate needed pliars about 18 inches long to get to it but again is another common fault apparantly and may not show on the OBD. Tech will probably know what i mean.

 

I assume your are talking about the Vent box system.

 

Could be, it was a thinish pipe about 3 to 4 inches long in about the last place anyone would look for one.

 

HMM, Thanks Edge, I will have to take a look at that and see what I can find. I already ran some injector cleaner before so I don't know if I should run some more. Any other possibilities about the ticking noise? Funny thing was I changed the oil only about a week ago and just happened to check the oil the other day and I was about a quart low. Maybe that signals something else that could be the bigger issue?? Thanks everyone!

 

The oil pan o-rings might be bad if the tapping is the lifters.

 

Is that a big or difficult job, I am getting a haynes manual today so maybe that should help or are there some procedures online that you would recommend? Are teh o rings something I can order from FCP or is that a dealer part?Thanks again

 

You should be able to order them from FCP.
https://volvoforums.com/m_6170/tm.htm
Its not the best but all I was able to do.