hard cold start 99 XC70

arda · Post by **arda** » 03 Oct 2010, 20:00

I have a 99 XC70 with ~168000 miles. I have done a fair amount of work on it within the last 2 years of my ownership with the help from this forum. An issue that has been bothering me lately is the occasional hard start problems. Here is a typical scenario;

-I haven't driven the car for 4-5 days. ( I ride my bicycle to work/school as long as its not raining--I suggest you all do the same as much as you can...ok ok done with bickering...

)
-Need to run to the grocery store or for whatever reason I decide to drive. Put the key in, then start
-Engine turns, then with a bit of vibration it starts
-As soon as it starts it feels like its misfiring
-I give it a little bit gas and with increasing engine speed it seems to get calmer-no rough idle
-Then right around at that time a loud "knocking/flapping/popping" sound comes--sounds like a stuck valve opening and letting air pass--this noise feels like its coming from underneath the car close to the passenger side...
-After that point the car is idling perfectly fine.

I checked all the ignition coils, spark plugs air intake, vacuum lines and everything seems to be in normal condition. Nothing broken, stripped, grounded.

This hard start does not happen when the car is warm. It starts right away without any vibration/shake. I must also mention this vibration can be pretty intense sometimes. It is almost as if the engine is about to drop out of the car. I never got a misfiring CEL when I experience this hard start problem.

There are a few problems with the car but this is the one that bothers me the most. To give some background if it would help you think of anything I might have missed;

-There is a pretty good possibility that I have a head gasket leak which leaks coolant into the combustion chambers. ( Moist piston tops, no leaks in coolant system but loss of coolant, low coolant light comes on/off when the engine has load-no coolant in oil though)
-Recently replaced the ETM with Xemodex
-New Bosch Copper spark plugs with the correct gapping
-New O2 sensors (front/back)
-New MAF
-Clean air filter
-Fresh oil

Given all the info, what might be the cause of this harsh start and the loud popping/clunk/knock/flap noise?

Post by **jblackburn** » 04 Oct 2010, 07:23

After sitting for that long, does the car start with a cloud of blue smoke if you rev it? After sitting for a few days, mine will get a bit grumpy too from oil leaking down into the cylinders, but never any noises like that.

You mention you think there might be a head gasket leak...you might want to do a compression/leakdown test to confirm this. Coolant can leak in any number of other places on a turbo model though, so crawl up underneath and have a look around.

arda · Post by **arda** » 04 Oct 2010, 08:07

There doesnt seem to be any blue smoke. Amazingly in 4000miles I never had to add any oil. Level is always right on the mark maybe getting abit close to the low end before an oil change. I dont think I burn oil, but there definately is some leaks around the oil cooler and usual other suspect. (No RMS though I dont think)

I will do the compression/leakdown test to see where the coolant is going. However if it is going into the cylinders wouldnt it be kinda sketch to test it that way. If all that coolant does go into like say one cylinder, wouldnt there be the risk of hydrolocking?

Post by **jblackburn** » 04 Oct 2010, 08:15

Crank the engine over before doing the compression test with the plugs removed - that'll shoot the fluid (if there is any) out of the cylinders. Coolant in a cylinder upon starting would definitely cause a misfire.

Then the compression test will tell you if there is a leak in the head gasket, which would be indicated by a low pressure on one or more cylinders.

geoney · Post by **geoney** » 04 Oct 2010, 13:45

It's funny,well,actually it's not that funny, but I have the same model,same mileage and the same problem!!!And I ride my bike too!It started about a month ago just for 4-5 seconds now it goes like that for 15 sec. and then turns to normal.If I don't drive for 6-7 hours does it again but shorter.Next morning again. I was thinking something in the likelihood of filters, air, fuel...Does that makes any sense?
Thanks.

George

Post by **jblackburn** » 04 Oct 2010, 13:48

Do you use an oil filter with a check valve in it? Without one, it'll make a pretty loud racket in the morning upon starting and isn't good for the engine.

arda · Post by **arda** » 04 Oct 2010, 15:32

I dont think there is a check valve in my oil filter. I use the MANN filter. Just like this one:
Mann Filter

I am due for an oil change soon, what oil filter has the check valve?

Post by **Pauloil** » 04 Oct 2010, 16:00

A Mann and OEM filters do, but this doesn't apply to your 99 with the cardboard insert.

arda · Post by **arda** » 04 Oct 2010, 16:48

Pauloil wrote:A Mann and OEM filters do, but this doesn't apply to your 99 with the cardboard insert.

FCP has this one: MANN which says it fits my 99 as well. But my car had the cartridge type since I got it and the spin cap is the original volvo. Sooo I guess it just takes the insert type, like the one I'm using now.

Post by **jblackburn** » 04 Oct 2010, 19:17

My fault, I always forget about the little differences between the years.